Astm a370 03A-Standard Test Methods and Definitions for STEEL

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Designation: A 370 – 03a
Standard Test Methods and Definitions for
Mechanical Testing of Steel Products 1
This standard is issued under the fixed designation A 370; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope*
1.1 These test methods2 cover procedures and definitions
for the mechanical testing of wrought and cast steels, stainless
steels, and related alloys. The various mechanical tests herein
described are used to determine properties required in the
product specifications. Variations in testing methods are to be
avoided, and standard methods of testing are to be followed to
obtain reproducible and comparable results. In those cases in
which the testing requirements for certain products are unique
or at variance with these general procedures, the product
specification testing requirements shall control.
1.2 The following mechanical tests are described:
Sections
Tension 5 to 13
Bend 14
Hardness 15
Brinell 16
Rockwell 17
Portable 18
Impact 19 to 28
Keywords 29
1.3 Annexes covering details peculiar to certain products
are appended to these test methods as follows:
Annex
Bar Products A1.1
Tubular Products Annex A2
Fasteners Annex A3
Round Wire Products Annex A4
Significance of Notched-Bar Impact Testing Annex A5
Converting Percentage Elongation of Round Specimens to
Equivalents for Flat Specimens
Annex A6
Testing Multi-Wire Strand Annex A7
Rounding of Test Data Annex A8
Methods for Testing Steel Reinforcing Bars Annex A9
Procedure for Use and Control of Heat-Cycle Simulation Annex A10
1.4 The values stated in inch-pound units are to be regarded
as the standard.
1.5 When this document is referenced in a metric product
specification, the yield and tensile values may be determined in
inch-pound (ksi) units then converted into SI (MPa) units. The
elongation determined in inch-pound gage lengths of 2 or 8 in.
may be reported in SI unit gage lengths of 50 or 200 mm,
respectively, as applicable. Conversely, when this document is
referenced in an inch-pound product specification, the yield
and tensile values may be determined in SI units then con-
verted into inch-pound units. The elongation determined in SI
unit gage lengths of 50 or 200 mm may be reported in
inch-pound gage lengths of 2 or 8 in., respectively, as appli-
cable.
1.6 Attention is directed to Practices A 880 and E 1595
when there may be a need for information on criteria for
evaluation of testing laboratories.
1.7 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
A 703/A 703M Specification for Steel Castings, General
Requirements, for Pressure-Containing Parts3
A 781/A 781M Specification for Castings, Steel and Alloy,
Common Requirements, for General Industrial Use3
A 833 Practice for Indentation Hardness of Metallic Mate-
rials by Comparison Hardness Testers4
A 880 Practice for Criteria for Use in Evaluation of Testing
Laboratories and Organizations for Examination and In-
spection of Steel, Stainless Steel, and Related Alloys5
E 4 Practices for Force Verification of Testing Machines6
E 6 Terminology Relating to Methods of Mechanical Test-
ing6
E 8 Test Methods for Tension Testing of Metallic Materials6
E 8M Test Methods for Tension Testing of Metallic Mate-
rials [Metric]6
E 10 Test Method for Brinell Hardness of Metallic Materi-
als61 These test methods and definitions are under the jurisdiction of ASTM
Committee A01 on Steel, Stainless Steel and Related Alloys and are the direct
responsibility of Subcommittee A01.13 on Mechanical and Chemical Testing and
Processing Methods of Steel Products and Processes.
Current edition approved Oct. 1, 2003. Published October 2003. Originally
approved in 1953. Last previous edition approved in 2003 as A 370 – 03.
2 For ASME Boiler and Pressure Vessel Codeapplications see related Specifi-
cation SA-370 in Section II of that Code.
3 Annual Book of ASTM Standards, Vol 01.02.
4 Annual Book of ASTM Standards, Vol 01.05.
5 Annual Book of ASTM Standards, Vol 01.03.
6 Annual Book of ASTM Standards, Vol 03.01.
1
*A Summary of Changes section appears at the end of this standard.
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E 18 Test Methods for Rockwell Hardness and Rockwell
Superficial Hardness of Metallic Materials6
E 23 Test Methods for Notched Bar Impact Testing of
Metallic Materials6
E 29 Practice for Using Significant Digits in Test Data to
Determine Conformance with Specifications7
E 83 Practice for Verification and Classification of Exten-
someters6
E 110 Test Method for Indentation Hardness of Metallic
Materials by Portable Hardness Testers6
E 190 Test Method for Guided Bend Test for Ductility of
Welds6
E 208 Test Method for Conducting Drop-Weight Test to
Determine Nil-Ductility Transition Temperature of Ferritic
Steels6
E 290 Test Method for Bend Test of Material for Ductility6
E 1595 Practice for Evaluating the Performance of Me-
chanical Testing Laboratories8
2.2 Other Document:
ASME Boiler and Pressure Vessel Code, Section VIII,
Division I, Part UG-849
3. General Precautions
3.1 Certain methods of fabrication, such as bending, form-
ing, and welding, or operations involving heating, may affect
the properties of the material under test. Therefore, the product
specifications cover the stage of manufacture at which me-
chanical testing is to be performed. The properties shown by
testing prior to fabrication may not necessarily be representa-
tive of the product after it has been completely fabricated.
3.2 Improper machining or preparation of test specimens
may give erroneous results. Care should be exercised to assure
good workmanship in machining. Improperly machined speci-
mens should be discarded and other specimens substituted.
3.3 Flaws in the specimen may also affect results. If any test
specimen develops flaws, the retest provision of the applicable
product specification shall govern.
3.4 If any test specimen fails because of mechanical reasons
such as failure of testing equipment or improper specimen
preparation, it may be discarded and another specimen taken.
4. Orientation of Test Specimens
4.1 The terms “longitudinal test” and “transverse test” are
used only in material specifications for wrought products and
are not applicable to castings. When such reference is made to
a test coupon or test specimen, the following definitions apply:
4.1.1 Longitudinal Test, unless specifically defined other-
wise, signifies that the lengthwise axis of the specimen is
parallel to the direction of the greatest extension of the steel
during rolling or forging. The stress applied to a longitudinal
tension test specimen is in the direction of the greatest
extension, and the axis of the fold of a longitudinal bend test
specimen is at right angles to the direction of greatest extension
(Fig. 1, Fig. 2a, and 2b).
4.1.2 Transverse Test, unless specifically defined otherwise,
signifies that the lengthwise axis of the specimen is at right
angles to the direction of the greatest extension of the steel
during rolling or forging. The stress applied to a transverse
tension test specimen is at right angles to the greatest exten-
sion, and the axis of the fold of a transverse bend test specimen
is parallelto the greatest extension (Fig. 1).
4.2 The terms “radial test” and “tangential test” are used in
material specifications for some wrought circular products and
are not applicable to castings. When such reference is made to
a test coupon or test specimen, the following definitions apply:
7 Annual Book of ASTM Standards, Vol 14.02.
8 Discontinued, see 2001Annual Book of ASTM Standards, Vol 03.01.
9 Available from American Society of Mechanical Engineers, 345 E. 47th Street,
New York, NY 10017.
FIG. 1 The Relation of Test Coupons and Test Specimens to
Rolling Direction or Extension (Applicable to General Wrought
Products)
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4.2.1 Radial Test, unless specifically defined otherwise,
signifies that the lengthwise axis of the specimen is perpen-
dicular to the axis of the product and coincident with one of the
radii of a circle drawn with a point on the axis of the product
as a center (Fig. 2a).
4.2.2 Tangential Test, unless specifically defined otherwise,
signifies that the lengthwise axis of the specimen is perpen-
dicular to a plane containing the axis of the product and tangent
to a circle drawn with a point on the axis of the product as a
center (Fig. 2a, 2b, 2c, and 2d).
TENSION TEST
5. Description
5.1 The tension test related to the mechanical testing of steel
products subjects a machined or full-section specimen of the
material under examination to a measured load sufficient to
cause rupture. The resulting properties sought are defined in
Terminology E 6.
5.2 In general, the testing equipment and methods are given
in Test Methods E 8. However, there are certain exceptions to
Test Methods E 8 practices in the testing of steel, and these are
covered in these test methods.
6. Terminology
6.1 For definitions of terms pertaining to tension testing,
including tensile strength, yield point, yield strength, elonga-
tion, and reduction of area, reference should be made to
Terminology E 6.
FIG. 2 Location of Longitudinal Tension Test Specimens in Rings Cut from Tubular Products
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7. Testing Apparatus and Operations
7.1 Loading Systems—There are two general types of load-
ing systems, mechanical (screw power) and hydraulic. These
differ chiefly in the variability of the rate of load application.
The older screw power machines are limited to a small number
of fixed free running crosshead speeds. Some modern screw
power machines, and all hydraulic machines permit stepless
variation throughout the range of speeds.
7.2 The tension testing machine shall be maintained in good
operating condition, used only in the proper loading range, and
calibrated periodically in accordance with the latest revision of
Practices E 4.
NOTE 1—Many machines are equipped with stress-strain recorders for
autographic plotting of stress-strain curves. It should be noted that some
recorders have a load measuring component entirely separate from the
load indicator of the testing machine. Such recorders are calibrated
separately.
7.3 Loading—It is the function of the gripping or holding
device of the testing machine to transmit the load from the
heads of the machine to the specimen under test. The essential
requirement is that the load shall be transmitted axially. This
implies that the centers of the action of the grips shall be in
alignment, insofar as practicable, with the axis of the specimen
at the beginning and during the test and that bending or
twisting be held to a minimum. For specimens with a reduced
section, gripping of the specimen shall be restricted to the grip
section. In the case of certain sections tested in full size,
nonaxial loading is unavoidable and in such cases shall be
permissible.
7.4 Speed of Testing—The speed of testing shall not be
greater than that at which load and strain readings can be made
accurately. In production testing, speed of testing is commonly
expressed: (1) in terms of free running crosshead speed (rate of
movement of the crosshead of the testing machine when not
under load), (2) in terms of rate of separation of the two heads
of the testing machine under load, (3) in terms of rate of
stressing the specimen, or (4) in terms of rate of straining the
specimen. The following limitations on the speed of testing are
recommended as adequate for most steel products:
NOTE 2—Tension tests using closed-loop machines (with feedback
control of rate) should not be performed using load control, as this mode
of testing will result in acceleration of the crosshead upon yielding and
elevation of the measured yield strength.
7.4.1 Any convenient speed of testing may be used up to
one half the specified yield point or yield strength. When this
point is reached, the free-running rate of separation of the
crossheads shall be adjusted so as not to exceed1⁄16 in. per min
per inch of reduced section, or the distance between the grips
for test specimens not having reduced sections. This speed
shall be maintained through the yield point or yield strength. In
determining the tensile strength, the free-running rate of
separation of the heads shall not exceed1⁄2 in. per min per inch
of reduced section, or the distance between the grips for test
specimens not having reduced sections. In any event, the
minimum speed of testing shall not be less than1⁄10 the
specified maximum rates for determining yield point or yield
strength and tensile strength.
7.4.2 It shall be permissible to set the speed of the testing
machine by adjusting the free running crosshead speed to the
above specified values, inasmuch as the rate of separation of
heads under load at these machine settings is less than the
specified values of free running crosshead speed.
7.4.3 As an alternative, if the machine is equipped with a
device to indicate the rate of loading, the speed of the machine
from half the specified yield point or yield strength through the
yield point or yield strength may be adjusted so that the rate of
stressing does not exceed 100 000 psi (690 MPa)/min. How-
ever, the minimum rate of stressing shall not be less than
10 000 psi (70 MPa)/min.
8. Test Specimen Parameters
8.1 Selection—Test coupons shall be selected in accordance
with the applicable product specifications.
8.1.1 Wrought Steels—Wrought steel products are usually
tested in the longitudinal direction, but in some cases, where
size permits and the service justifies it, testing is in the
transverse, radial, or tangential directions (see Fig. 1 and Fig.
2).
8.1.2 Forged Steels—For open die forgings, the metal for
tension testing is usually provided by allowing extensions or
prolongations on one or both ends of the forgings, either on all
or a representative number as provided by the applicable
product specifications. Test specimens are normally taken at
mid-radius. Certain product specifications permit the use of a
representative bar or the destruction of a production part for
test purposes. For ring or disk-like forgings test metal is
provided by increasing the diameter, thickness, or length of the
forging. Upset disk or ring forgings, which are worked or
extended by forging in a direction perpendicular to the axis of
the forging, usually have their principal extension along
concentric circles and for such forgings tangential tension
specimens are obtained from extra metal on the periphery or
end of the forging. For some forgings, such as rotors, radial
tension tests are required. In such cases the specimens are cut
or trepanned from specified locations.
8.1.3 Cast Steels—Test coupons for castings from which
tension test specimens are prepared shall be in accordance with
the requirements of Specifications A 703/A 703M or A781/
A 781M, as applicable.8.2 Size and Tolerances—Test specimens shall be the full
thickness or section of material as-rolled, or may be machined
to the form and dimensions shown in Figs. 3-6, inclusive. The
selection of size and type of specimen is prescribed by the
applicable product specification. Full section specimens shall
be tested in 8-in. (200-mm) gage length unless otherwise
specified in the product specification.
8.3 Procurement of Test Specimens—Specimens shall be
sheared, blanked, sawed, trepanned, or oxygen-cut from por-
tions of the material. They are usually machined so as to have
a reduced cross section at mid-length in order to obtain uniform
distribution of the stress over the cross section and to localize
the zone of fracture. When test coupons are sheared, blanked,
sawed, or oxygen-cut, care shall be taken to remove by
machining all distorted, cold-worked, or heat-affected areas
from the edges of the section used in evaluating the test.
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8.4 Aging of Test Specimens—Unless otherwise specified, it
shall be permissible to age tension test specimens. The time-
temperature cycle employed must be such that the effects of
previous processing will not be materially changed. It may be
accomplished by aging at room temperature 24 to 48 h, or in
shorter time at moderately elevated temperatures by boiling in
water, heating in oil or in an oven.
8.5 Measurement of Dimensions of Test Specimens:
8.5.1 Standard Rectangular Tension Test Specimens—These
forms of specimens are shown in Fig. 3. To determine the
DIMENSIONS
Standard Specimens Subsize Specimen
Plate-Type,
11⁄2-in. Wide
Sheet-Type,
1⁄2-in. Wide
1⁄4-in. Wide
in. mm in. mm in. mm
G—Gage length (Notes 1 and 2) 8.00 6 0.01 200 6 0.25 2.000 6 0.005 50.0 6 0.10 1.000 6 0.003 25.0 6 0.08
W—Width (Notes 3, 5, and 6) 11⁄2 + 1⁄8
− 1⁄4
40 + 3
− 6
0.500 6 0.010 12.5 6 0.25 0.250 6 0.002 6.25 6 0.05
T—Thickness (Note 7) Thickness of Material
R—Radius of fillet, min (Note 4) 1⁄2 13 1⁄2 13 1⁄4 6
L—Over-all length, min (Notes 2 and 8) 18 450 8 200 4 100
A—Length of reduced section, min 9 225 21⁄4 60 11⁄4 32
B—Length of grip section, min (Note 9) 3 75 2 50 11⁄4 32
C—Width of grip section, approximate
(Notes 4, 10, and 11)
2 50 3⁄4 20 3⁄8 10
NOTE 1—For the 11⁄2-in. (40-mm) wide specimen, punch marks for measuring elongation after fracture shall be made on the flat or on the edge of the
specimen and within the reduced section. Either a set of nine or more punch marks 1 in. (25 mm) apart, or one or more pairs of punch marks 8 in. (200
mm) apart may be used.
NOTE 2—For the1⁄2-in. (12.5-mm) wide specimen, gage marks for measuring the elongation after fracture shall be made on the1⁄2-inch (12.5-mm) face
or on the edge of the specimen and within the reduced section. Either a set of three or more marks 1.0 in. (25 mm) apart or one or more pairs of marks
2 in. (50 mm) apart may be used.
NOTE 3—For the three sizes of specimens, the ends of the reduced section shall not differ in width by more than 0.004, 0.002 or 0.001 in. (0.10, 0.05
or 0.025 mm), respectively. Also, there may be a gradual decrease in width from the ends to the center, but the width at either end shall not be more than
0.015 in., 0.005 in., or 0.003 in. (0.40, 0.10 or 0.08 mm), respectively, larger than the width at the center.
NOTE 4—For each specimen type, the radii of all fillets shall be equal to each other with a tolerance of 0.05 in. (1.25 mm), and the centers of curvature
of the two fillets at a particular end shall be located across from each other (on a line perpendicular to the centerline) within a tolerance of 0.10 in. (2.5
mm).
NOTE 5—For each of the three sizes of specimens, narrower widths (W andC) may be used when necessary. In such cases the width of the reduced
section should be as large as the width of the material being tested permits; however, unless stated specifically, the requirements for elongation in aproduct
specification shall not apply when these narrower specimens are used. If the width of the material is less thanW, the sides may be parallel throughout
the length of the specimen.
NOTE 6—The specimen may be modified by making the sides parallel throughout the length of the specimen, the width and tolerances being the same
as those specified above. When necessary a narrower specimen may be used, in which case the width should be as great as the width of the material being
tested permits. If the width is 11⁄2 in. (38 mm) or less, the sides may be parallel throughout the length of the specimen.
NOTE 7—The dimensionT is the thickness of the test specimen as provided for in the applicable material specifications. Minimum nominal thickness
of 11⁄2-in. (40-mm) wide specimens shall be3⁄16 in. (5 mm), except as permitted by the product specification. Maximum nominal thickness of1⁄2-in.
(12.5-mm) and1⁄4-in. (6-mm) wide specimens shall be3⁄4 in. (19 mm) and1⁄4 in. (6 mm), respectively.
NOTE 8—To aid in obtaining axial loading during testing of1⁄4-in. (6-mm) wide specimens, the overall length should be as the material will permit.
NOTE 9—It is desirable, if possible, to make the length of the grip section large enough to allow the specimen to extend into the grips a distance equal
to two thirds or more of the length of the grips. If the thickness of1⁄2-in. (13-mm) wide specimens is over3⁄8 in. (10 mm), longer grips and correspondingly
longer grip sections of the specimen may be necessary to prevent failure in the grip section.
NOTE 10—For standard sheet-type specimens and subsize specimens the ends of the specimen shall be symmetrical with the center line of the reduced
section within 0.01 and 0.005 in. (0.25 and 0.13 mm), respectively. However, for steel if the ends of the1⁄2-in. (12.5-mm) wide specimen are symmetrical
within 0.05 in. (1.0 mm) a specimen may be considered satisfactory for all but referee testing.
NOTE 11—For standard plate-type specimens the ends of the specimen shall be symmetrical with the center line of the reduced section within 0.25 in.
(6.35 mm) except for referee testing in which case the ends of the specimen shall be symmetrical with the center line of the reduced section within 0.10
in. (2.5 mm).
FIG. 3 Rectangular Tension Test Specimens
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cross-sectional area, the center width dimension shall be
measured to the nearest 0.005 in. (0.13 mm) for the 8-in.
(200-mm) gage length specimen and 0.001 in. (0.025 mm) for
the 2-in. (50-mm) gage length specimen in Fig. 3. The center
thickness dimension shall be measured to the nearest 0.001 in.
for both specimens.
8.5.2 Standard Round Tension Test Specimens—These
forms of specimens are shown in Fig. 4 and Fig. 5. To
determine the cross-sectional area, the diameter shall be
measured at the center of the gage length to the nearest 0.001
in. (0.025 mm) (see Table 1).
8.6 General—Test specimens shall be either substantially
full size or machined, as prescribed in the product specifica-
tions for the material being tested.
8.6.1 Improperly prepared test specimens often cause unsat-
isfactory test results. It is important, therefore, that care be
exercised in the preparation of specimens, particularly in the
machining, to assure good workmanship.
8.6.2 It is desirable to have the cross-sectional area of the
specimen smallest at the center of the gage length to ensure
fracture within the gage length. This is provided for by the
taper in the gage length permitted for each of the specimens
described in the following sections.
8.6.3 For brittle materials it is desirable to have fillets of
large radius at the ends of the gage length.
9. Plate-Type Specimen
9.1 The standard plate-type test specimen isshown in Fig. 3.
This specimen is used for testing metallic materials in the form
of plate, structural and bar-size shapes, and flat material having
a nominal thickness of3⁄16 in. (5 mm) or over. When product
specifications so permit, other types of specimens may be used.
NOTE 3—When called for in the product specification, the 8-in. gage
length specimen of Fig. 3 may be used for sheet and strip material.
10. Sheet-Type Specimen
10.1 The standard sheet-type test specimen is shown in Fig.
3. This specimen is used for testing metallic materials in the
form of sheet, plate, flat wire, strip, band, and hoop ranging in
nominal thickness from 0.005 to3⁄4 in. (0.13 to 19 mm). When
product specifications so permit, other types of specimens may
be used, as provided in Section 9 (see Note 3).
DIMENSIONS
Nominal Diameter
Standard Specimen Small-Size Specimens Proportional to Standard
in. mm in. mm in. mm in. mm in. mm
0.500 12.5 0.350 8.75 0.250 6.25 0.160 4.00 0.113 2.50
G—Gage length 2.006
0.005
50.0 6
0.10
1.4006
0.005
35.0 6
0.10
1.0006
0.005
25.0 6
0.10
0.6406
0.005
16.0 6
0.10
0.4506
0.005
10.0 6
0.10
D—Diameter (Note 1) 0.5006
0.010
12.56
0.25
0.3506
0.007
8.75 6
0.18
0.2506
0.005
6.25 6
0.12
0.1606
0.003
4.00 6
0.08
0.1136
0.002
2.50 6
0.05
R—Radius of fillet, min 3⁄8 10 1⁄4 6 3⁄16 5 5⁄32 4 3⁄32 2
A—Length of reduced section,
min (Note 2)
21⁄4 60 13⁄4 45 11⁄4 32 3⁄4 20 5⁄8 16
NOTE 1—The reduced section may have a gradual taper from the ends toward the center, with the ends not more than 1 percent larger in diameter than
the center (controlling dimension).
NOTE 2—If desired, the length of the reduced section may be increased to accommodate an extensometer of any convenient gage length. Reference
marks for the measurement of elongation should, nevertheless, be spaced at the indicated gage length.
NOTE 3—The gage length and fillets shall be as shown, but the ends may be of any form to fit the holders of the testing machine in such a way that
the load shall be axial (see Fig. 9). If the ends are to be held in wedge grips it is desirable, if possible, to make the length of the grip section great enough
to allow the specimen to extend into the grips a distance equal to two thirds or more of the length of the grips.
NOTE 4—On the round specimens in Fig. 5 and Fig. 6, the gage lengths are equal to four times the nominal diameter. In some product specifications
other specimens may be provided for, but unless the 4-to-1 ratio is maintained within dimensional tolerances, the elongation values may not be comparable
with those obtained from the standard test specimen.
NOTE 5—The use of specimens smaller than 0.250-in. (6.25-mm) diameter shall be restricted to cases when the material to be tested is of insufficient
size to obtain larger specimens or when all parties agree to their use for acceptance testing. Smaller specimens require suitable equipment and greater
skill in both machining and testing.
NOTE 6—Five sizes of specimens often used have diameters of approximately 0.505, 0.357, 0.252, 0.160, and 0.113 in., the reason being to permit easy
calculations of stress from loads, since the corresponding cross sectional areas are equal or close to 0.200, 0.100, 0.0500, 0.0200, and 0.0100 in.2,
respectively. Thus, when the actual diameters agree with these values, the stresses (or strengths) may be computed using the simple multiplying factors
5, 10, 20, 50, and 100, respectively. (The metric equivalents of these fixed diameters do not result in correspondingly convenient cross sectional area and
multiplying factors.)
FIG. 4 Standard 0.500-in. (12.5-mm) Round Tension Test Specimen with 2-in. (50-mm) Gage Length and Examples of Small-Size
Specimens Proportional to the Standard Specimens
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11. Round Specimens
11.1 The standard 0.500-in. (12.5-mm) diameter round test
specimen shown in Fig. 4 is used quite generally for testing
metallic materials, both cast and wrought.
11.2 Fig. 4 also shows small size specimens proportional to
the standard specimen. These may be used when it is necessary
to test material from which the standard specimen or specimens
shown in Fig. 3 cannot be prepared. Other sizes of small round
specimens may be used. In any such small size specimen it is
important that the gage length for measurement of elongation
be four times the diameter of the specimen (see Note 4, Fig. 4).
11.3 The shape of the ends of the specimens outside of the
gage length shall be suitable to the material and of a shape to
fit the holders or grips of the testing machine so that the loads
are applied axially. Fig. 5 shows specimens with various types
of ends that have given satisfactory results.
12. Gage Marks
12.1 The specimens shown in Figs. 3-6 shall be gage
marked with a center punch, scribe marks, multiple device, or
drawn with ink. The purpose of these gage marks is to
determine the percent elongation. Punch marks shall be light,
sharp, and accurately spaced. The localization of stress at the
marks makes a hard specimen susceptible to starting fracture at
the punch marks. The gage marks for measuring elongation
after fracture shall be made on the flat or on the edge of the flat
tension test specimen and within the parallel section; for the
8-in. gage length specimen, Fig. 3, one or more sets of 8-in.
gage marks may be used, intermediate marks within the gage
length being optional. Rectangular 2-in. gage length speci-
mens, Fig. 3, and round specimens, Fig. 4, are gage marked
with a double-pointed center punch or scribe marks. One or
more sets of gage marks may be used; however, one set must
be approximately centered in the reduced section. These same
precautions shall be observed when the test specimen is full
section.
13. Determination of Tensile Properties
13.1 Yield Point—Yield point is the first stress in a material,
less than the maximum obtainable stress, at which an increase
in strain occurs without an increase in stress. Yield point is
intended for application only for materials that may exhibit the
unique characteristic of showing an increase in strain without
an increase in stress. The stress-strain diagram is characterized
DIMENSIONS
Specimen 1 Specimen 2 Specimen 3 Specimen 4 Specimen 5
in. mm in. mm in. mm in. mm in. mm
G—Gage length 2.0006
0.005
50.0 6
0.10
2.0006
0.005
50.0 6
0.10
2.0006
0.005
50.0 6
0.10
2.0006
0.005
50.0 6
0.10
2.006
0.005
50.0 6
0.10
D—Diameter (Note 1) 0.500 6
0.010
12.56
0.25
0.500 6
0.010
12.56
0.25
0.500 6
0.010
12.56
0.25
0.500 6
0.010
12.56
0.25
0.5006
0.010
12.5 6
0.25
R—Radius of fillet, min 3⁄8 10 3⁄8 10 1⁄16 2 3⁄8 10 3⁄8 10
A—Length of reduced
section
21⁄4 , min 60, min 21⁄4 , min 60, min 4, ap-
proxi-
mately
100, ap-
proxi-
mately
21⁄4 , min 60, min 21⁄4 , min 60, min
L—Overall length, approximate 5 125 51⁄2 140 51⁄2 140 43⁄4 120 91⁄2 240
B—Grip section
(Note 2)
13⁄8 , ap-
proxi-
mately
35, ap-
proxi-
mately
1, ap-
proxi-
mately
25, ap-
proxi-
mately
3⁄4 , ap-
proxi-
mately
20, ap-
proxi-
mately
1⁄2 , ap-
proxi-
mately
13, ap-
proxi-
mately
3, min 75, min
C—Diameter of end section 3⁄4 20 3⁄4 20 23⁄32 18 7⁄8 22 3⁄4 20
E—Length of shoulder and
fillet section, approximate
. . . . . . 5⁄8 16 . . . . . . 3⁄4 20 5⁄8 16
F—Diameter of shoulder . . . . . . 5⁄8 16 . . . . . . 5⁄8 16 19⁄32 15
NOTE 1—The reduced section may have a gradual taper from the ends toward the center with the ends not more than 0.005 in. (0.10 mm) larger in
diameter than the center.
NOTE 2—On Specimen 5 it is desirable, if possible, to make the length of the grip section great enough to allow the specimen to extend into the grips
a distance equal to two thirds or more of the length of the grips.
NOTE 3—The types of ends shown are applicable for the standard 0.500-in. round tension test specimen; similar types can be used for subsize
specimens.The use of UNF series of threads (3⁄4 by 16,1⁄2 by 20,3⁄8 by 24, and1⁄4 by 28) is suggested for high-strength brittle materials to avoid fracture
in the thread portion.
FIG. 5 Suggested Types of Ends for Standard Round Tension Test Specimens
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by a sharp knee or discontinuity. Determine yield point by one
of the following methods:
13.1.1 Drop of the Beam or Halt of the Pointer Method—In
this method, apply an increasing load to the specimen at a
uniform rate. When a lever and poise machine is used, keep the
beam in balance by running out the poise at approximately a
steady rate. When the yield point of the material is reached, the
increase of the load will stop, but run the poise a trifle beyond
the balance position, and the beam of the machine will drop for
a brief but appreciable interval of time. When a machine
equipped with a load-indicating dial is used there is a halt or
hesitation of the load-indicating pointer corresponding to the
DIMENSIONS
Specimen 1 Specimen 2 Specimen 3
in. mm in. mm in. mm
G—Length of parallel Shall be equal to or greater than diameter D
D—Diameter 0.500 6 0.010 12.56 0.25 0.750 6 0.015 20.0 6 0.40 1.25 6 0.025 30.0 6 0.60
R—Radius of fillet, min 1 25 1 25 2 50
A—Length of reduced section, min 11⁄4 32 11⁄2 38 21⁄4 60
L—Over-all length, min 33⁄4 95 4 100 63⁄8 160
B—Grip section, approximate 1 25 1 25 13⁄4 45
C—Diameter of end section, approximate 3⁄4 20 11⁄8 30 17⁄8 48
E—Length of shoulder, min 1⁄4 6 1⁄4 6 5⁄16 8
F—Diameter of shoulder 5⁄8 6 1⁄64 16.0 6 0.40 15⁄16 6 1⁄64 24.0 6 0.40 17⁄16 6 1⁄64 36.5 6 0.40
NOTE 1—The reduced section and shoulders (dimensionsA, D, E, F, G,andR) shall be shown, but the ends may be of any form to fit the holders of
the testing machine in such a way that the load shall be axial. Commonly the ends are threaded and have the dimensionsB andC given above.
FIG. 6 Standard Tension Test Specimens for Cast Iron
TABLE 1 Multiplying Factors to Be Used for Various Diameters of Round Test Specimens
Standard Specimen Small Size Specimens Proportional to Standard
0.500 in. Round 0.350 in. Round 0.250 in. Round
Actual
Diameter,
in.
Area,
in.2
Multiplying
Factor
Actual
Diameter,
in.
Area,
in.2
Multiplying
Factor
Actual
Diameter,
in.
Area,
in.2
Multiplying
Factor
0.490 0.1886 5.30 0.343 0.0924 10.82 0.245 0.0471 21.21
0.491 0.1893 5.28 0.344 0.0929 10.76 0.246 0.0475 21.04
0.492 0.1901 5.26 0.345 0.0935 10.70 0.247 0.0479 20.87
0.493 0.1909 5.24 0.346 0.0940 10.64 0.248 0.0483 20.70
0.494 0.1917 5.22 0.347 0.0946 10.57 0.249 0.0487 20.54
0.495 0.1924 5.20 0.348 0.0951 10.51 0.250 0.0491 20.37
0.496 0.1932 5.18 0.349 0.0957 10.45 0.251 0.0495 20.21
(0.05)A (20.0)A
0.497 0.1940 5.15 0.350 0.0962 10.39 0.252 0.0499 20.05
(0.05)A (20.0)A
0.498 0.1948 5.13 0.351 0.0968 10.33 0.253 0.0503 19.89
(0.05)A (20.0)A
0.499 0.1956 5.11 0.352 0.0973 10.28 0.254 0.0507 19.74
0.500 0.1963 5.09 0.353 0.0979 10.22 0.255 0.0511 19.58
0.501 0.1971 5.07 0.354 0.0984 10.16 . . . . . . . . .
0.502 0.1979 5.05 0.355 0.0990 10.10 . . . . . . . . .
0.503 0.1987 5.03 0.356 0.0995 10.05 . . . . . . . . .
(0.1)A (10.0)A . . . . . . . . .
0.504 0.1995 5.01 0.357 0.1001 9.99 . . . . . . . . .
(0.2)A (5.0)A (0.1)A (10.0)A . . . . . . . . .
0.505 0.2003 4.99 . . . . . . . . . . . . . . . . . .
(0.2)A (5.0)A
0.506 0.2011 4.97 . . . . . . . . . . . . . . . . . .
(0.2)A (5.0)A
0.507 0.2019 4.95 . . . . . . . . . . . . . . . . . .
0.508 0.2027 4.93 . . . . . . . . . . . . . . . . . .
0.509 0.2035 4.91 . . . . . . . . . . . . . . . . . .
0.510 0.2043 4.90 . . . . . . . . . . . . . . . . . .
A The values in parentheses may be used for ease in calculation of stresses, in pounds per square inch, as permitted in 5 of Fig. 4.
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drop of the beam. Note the load at the “drop of the beam” or
the “halt of the pointer” and record the corresponding stress as
the yield point.
13.1.2 Autographic Diagram Method—When a sharp-
kneed stress-strain diagram is obtained by an autographic
recording device, take the stress corresponding to the top of the
knee (Fig. 7), or the stress at which the curve drops as the yield
point.
13.1.3 Total Extension Under Load Method—When testing
material for yield point and the test specimens may not exhibit
a well-defined disproportionate deformation that characterizes
a yield point as measured by the drop of the beam, halt of the
pointer, or autographic diagram methods described in 13.1.1
and 13.1.2, a value equivalent to the yield point in its practical
significance may be determined by the following method and
may be recorded as yield point: Attach a Class C or better
extensometer (Note 4 and Note 5) to the specimen. When the
load producing a specified extension (Note 6) is reached record
the stress corresponding to the load as the yield point (Fig. 8).
NOTE 4—Automatic devices are available that determine the load at the
specified total extension without plotting a stress-strain curve. Such
devices may be used if their accuracy has been demonstrated. Multiplying
calipers and other such devices are acceptable for use provided their
accuracy has been demonstrated as equivalent to a Class C extensometer.
NOTE 5—Reference should be made to Practice E 83.
NOTE 6—For steel with a yield point specified not over 80 000 psi (550
MPa), an appropriate value is 0.005 in./in. of gage length. For values
above 80 000 psi, this method is not valid unless the limiting total
extension is increased.
NOTE 7—The shape of the initial portion of an autographically deter-
mined stress-strain (or a load-elongation) curve may be influenced by
numerous factors such as the seating of the specimen in the grips, the
straightening of a specimen bent due to residual stresses, and the rapid
loading permitted in 7.4.1. Generally, the aberrations in this portion of the
curve should be ignored when fitting a modulus line, such as that used to
determine the extension-under-load yield, to the curve.
13.2 Yield Strength—Yield strength is the stress at which a
material exhibits a specified limiting deviation from the pro-
portionality of stress to strain. The deviation is expressed in
terms of strain, percent offset, total extension under load, etc.
Determine yield strength by one of the following methods:
13.2.1 Offset Method—To determine the yield strength by
the “offset method,” it is necessary to secure data (autographic
or numerical) from which a stress-strain diagram with a distinct
modulus characteristic of the material being tested may be
drawn. Then on the stress-strain diagram (Fig. 9) lay offOm
equal to the specified value of the offset, drawmn parallel to
OA, and thus locater, the intersection ofmn with the
stress-strain curve corresponding to loadR, which is the
yield-strength load. In recording values of yield strength
obtained by this method, the value of offset specified or used,
or both, shall be stated in parentheses after the term yield
strength, for example:
Yield strength~0.2 % offset! 5 52 000 psi~360 MPa! (1)
When the offset is 0.2 % or larger, the extensometer used
shall qualify as a Class B2 device over a strain range of 0.05 to
1.0 %. If a smaller offset is specified, it may be necessary to
specify a more accurate device (that is, a Class B1 device) or
reduce the lower limit of the strain range (for example, to
0.01 %) or both. See also Note 9 for automatic devices.
NOTE 8—For stress-strain diagrams not containing a distinct modulus,
such as for some cold-worked materials, it is recommended that the
extension under load method be utilized. If the offset method is used for
materials without a distinct modulus, a modulus value appropriate for the
materialbeing tested should be used: 30 000 000 psi (207 000 MPa) for
carbon steel; 29 000 000 psi (200 000 MPa) for ferritic stainless steel;
28 000 000 psi (193 000 MPa) for austenitic stainless steel. For special
alloys, the producer should be contacted to discuss appropriate modulus
values.
13.2.2 Extension Under Load Method—For tests to deter-
mine the acceptance or rejection of material whose stress-strain
characteristics are well known from previous tests of similar
material in which stress-strain diagrams were plotted, the total
strain corresponding to the stress at which the specified offset
(see Note 9 and Note 10) occurs will be known within
satisfactory limits. The stress on the specimen, when this total
FIG. 7 Stress-Strain Diagram Showing Yield Point Corresponding
with Top of Knee
FIG. 8 Stress-Strain Diagram Showing Yield Point or Yield
Strength by Extension Under Load Method
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strain is reached, is the value of the yield strength. In recording
values of yield strength obtained by this method, the value of
“extension” specified or used, or both, shall be stated in
parentheses after the term yield strength, for example:
Yield strength~0.5 % EUL! 5 52 000 psi~360 MPa! (2)
The total strain can be obtained satisfactorily by use of a
Class B1 extensometer (Note 4, Note 5, and Note 7).
NOTE 9—Automatic devices are available that determine offset yield
strength without plotting a stress-strain curve. Such devices may be used
if their accuracy has been demonstrated.
NOTE 10—The appropriate magnitude of the extension under load will
obviously vary with the strength range of the particular steel under test. In
general, the value of extension under load applicable to steel at any
strength level may be determined from the sum of the proportional strain
and the plastic strain expected at the specified yield strength. The
following equation is used:
Extension under load, in./in. of gage length5 ~YS/E! 1 r (3)
where:
YS = specified yield strength, psi or MPa,
E = modulus of elasticity, psi or MPa, and
r = limiting plastic strain, in./in.
13.3 Tensile Strength— Calculate the tensile strength by
dividing the maximum load the specimen sustains during a
tension test by the original cross-sectional area of the speci-
men.
13.4 Elongation:
13.4.1 Fit the ends of the fractured specimen together
carefully and measure the distance between the gage marks to
the nearest 0.01 in. (0.25 mm) for gage lengths of 2 in. and
under, and to the nearest 0.5 % of the gage length for gage
lengths over 2 in. A percentage scale reading to 0.5 % of the
gage length may be used. The elongation is the increase in
length of the gage length, expressed as a percentage of the
original gage length. In recording elongation values, give both
the percentage increase and the original gage length.
13.4.2 If any part of the fracture takes place outside of the
middle half of the gage length or in a punched or scribed mark
within the reduced section, the elongation value obtained may
not be representative of the material. If the elongation so
measured meets the minimum requirements specified, no
further testing is indicated, but if the elongation is less than the
minimum requirements, discard the test and retest.
13.4.3 Automated tensile testing methods using extensom-
eters allow for the measurement of elongation in a method
described below. Elongation may be measured and reported
either this way, or as in the method described above, fitting the
broken ends together. Either result is valid.
13.4.4 Elongation at fracture is defined as the elongation
measured just prior to the sudden decrease in force associated
with fracture. For many ductile materials not exhibiting a
sudden decrease in force, the elongation at fracture can be
taken as the strain measured just prior to when the force falls
below 10 % of the maximum force encountered during the test.
13.4.4.1 Elongation at fracture shall include elastic and
plastic elongation and may be determined with autographic or
automated methods using extensometers verified over the
strain range of interest. Use a class B2 or better extensometer
for materials having less than 5 % elongation; a class C or
better extensometer for materials having elongation greater
than or equal to 5 % but less than 50 %; and a class D or better
extensometer for materials having 50 % or greater elongation.
In all cases, the extensometer gage length shall be the nominal
gage length required for the specimen being tested. Due to the
lack of precision in fitting fractured ends together, the elonga-
tion after fracture using the manual methods of the preceding
paragraphs may differ from the elongation at fracture deter-
mined with extensometers.
13.4.4.2 Percent elongation at fracture may be calculated
directly from elongation at fracture data and be reported
instead of percent elongation as calculated in 13.4.1. However,
these two parameters are not interchangeable. Use of the
elongation at fracture method generally provides more repeat-
able results.
13.5 Reduction of Area—Fit the ends of the fractured
specimen together and measure the mean diameter or the width
and thickness at the smallest cross section to the same accuracy
as the original dimensions. The difference between the area
thus found and the area of the original cross section expressed
as a percentage of the original area is the reduction of area.
BEND TEST
14. Description
14.1 The bend test is one method for evaluating ductility,
but it cannot be considered as a quantitative means of predict-
ing service performance in bending operations. The severity of
the bend test is primarily a function of the angle of bend and
inside diameter to which the specimen is bent, and of the cross
section of the specimen. These conditions are varied according
to location and orientation of the test specimen and the
chemical composition, tensile properties, hardness, type, and
FIG. 9 Stress-Strain Diagram for Determination of Yield Strength
by the Offset Method
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quality of the steel specified. Method E 190 and Test Method
E 290 may be consulted for methods of performing the test.
14.2 Unless otherwise specified, it shall be permissible to
age bend test specimens. The time-temperature cycle employed
must be such that the effects of previous processing will not be
materially changed. It may be accomplished by aging at room
temperature 24 to 48 h, or in shorter time at moderately
elevated temperatures by boiling in water or by heating in oil
or in an oven.
14.3 Bend the test specimen at room temperature to an
inside diameter, as designated by the applicable product
specifications, to the extent specified without major cracking
on the outside of the bent portion. The speed of bending is
ordinarily not an important factor.
HARDNESS TEST
15. General
15.1 A hardness test is a means of determining resistance to
penetration and is occasionally employed to obtain a quick
approximation of tensile strength. Table 2, Table 3, Table 4,
and Table 5 are for the conversion of hardness measurements
from one scale to another or to approximate tensile strength.
These conversion values have been obtained from computer-
generated curves and are presented to the nearest 0.1 point to
permit accurate reproduction of those curves. Since all con-
verted hardness values must be considered approximate, how-
ever, all converted Rockwell hardness numbers shall be
rounded to the nearest whole number.
15.2 Hardness Testing:
15.2.1 If the product specification permits alternative hard-
ness testing to determine conformance to a specified hardness
requirement, the conversions listed in Table 2,Table 3, Table 4,
and Table 5 shall be used.
15.2.2 When recording converted hardness numbers, the
measured hardness and test scale shall be indicated in paren-
theses, for example: 353 HB (38 HRC). This means that a
hardness value of 38 was obtained using the Rockwell C scale
and converted to a Brinell hardness of 353.
16. Brinell Test
16.1 Description:
16.1.1 A specified load is applied to a flat surface of the
specimen to be tested, through a hard ball of specified diameter.
The average diameter of the indentation is used as a basis for
calculation of the Brinell hardness number. The quotient of the
applied load divided by the area of the surface of the
indentation, which is assumed to be spherical, is termed the
Brinell hardness number (HB) in accordance with the follow-
ing equation:
HB 5 P/@~pD/2!~D 2 =D 2 2 d2!# (4)
where:
HB = Brinell hardness number,
P = applied load, kgf,
D = diameter of the steel ball, mm, and
d = average diameter of the indentation, mm.
NOTE 11—The Brinell hardness number is more conveniently secured
from standard tables such as Table 6, which show numbers corresponding
to the various indentation diameters, usually in increments of 0.05 mm.
NOTE 12—In Test Method E 10 the values are stated in SI units,
whereas in this section kg/m units are used.
16.1.2 The standard Brinell test using a 10-mm ball em-
ploys a 3000-kgf load for hard materials and a 1500 or 500-kgf
load for thin sections or soft materials (see Annex on Steel
Tubular Products). Other loads and different size indentors may
be used when specified. In recording hardness values, the
diameter of the ball and the load must be stated except when a
10-mm ball and 3000-kgf load are used.
16.1.3 A range of hardness can properly be specified only
for quenched and tempered or normalized and tempered
material. For annealed material a maximum figure only should
be specified. For normalized material a minimum or a maxi-
mum hardness may be specified by agreement. In general, no
hardness requirements should be applied to untreated material.
16.1.4 Brinell hardness may be required when tensile prop-
erties are not specified.
16.2 Apparatus—Equipment shall meet the following re-
quirements:
16.2.1 Testing Machine— A Brinell hardness testing ma-
chine is acceptable for use over a loading range within which
its load measuring device is accurate to61 %.
16.2.2 Measuring Microscope—The divisions of the mi-
crometer scale of the microscope or other measuring devices
used for the measurement of the diameter of the indentations
shall be such as to permit the direct measurement of the
diameter to 0.1 mm and the estimation of the diameter to 0.05
mm.
NOTE 13—This requirement applies to the construction of the micro-
scope only and is not a requirement for measurement of the indentation,
see 16.4.3.
16.2.3 Standard Ball— The standard ball for Brinell hard-
ness testing is 10 mm (0.3937 in.) in diameter with a deviation
from this value of not more than 0.005 mm (0.0004 in.) in any
diameter. A ball suitable for use must not show a permanent
change in diameter greater than 0.01 mm (0.0004 in.) when
pressed with a force of 3000 kgf against the test specimen.
16.3 Test Specimen—Brinell hardness tests are made on
prepared areas and sufficient metal must be removed from the
surface to eliminate decarburized metal and other surface
irregularities. The thickness of the piece tested must be such
that no bulge or other marking showing the effect of the load
appears on the side of the piece opposite the indentation.
16.4 Procedure:
16.4.1 It is essential that the applicable product specifica-
tions state clearly the position at which Brinell hardness
indentations are to be made and the number of such indenta-
tions required. The distance of the center of the indentation
from the edge of the specimen or edge of another indentation
must be at least two and one-half times the diameter of the
indentation.
16.4.2 Apply the load for a minimum of 15 s.
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TABLE 2 Approximate Hardness Conversion Numbers for Nonaustenitic Steels A (Rockwell C to Other Hardness Numbers)
Rockwell C
Scale, 150-kgf
Load, Diamond
Penetrator
Vickers
Hardness
Number
Brinell
Hardness,
3000-kgf Load,
10-mm Ball
Knoop
Hardness,
500-gf Load
and Over
Rockwell
A Scale,
60-kgf Load,
Diamond
Penetrator
Rockwell Superficial Hardness
15N Scale,
15-kgf
Load,
Diamond
Penetrator
30N Scale
30-kgf
Load,
Diamond
Penetrator
45N Scale,
45-kgf
Load,
Diamond
Penetrator
Approximate
Tensile
Strength,
ksi (MPa)
68 940 . . . 920 85.6 93.2 84.4 75.4 . . .
67 900 . . . 895 85.0 92.9 83.6 74.2 . . .
66 865 . . . 870 84.5 92.5 82.8 73.3 . . .
65 832 739 846 83.9 92.2 81.9 72.0 . . .
64 800 722 822 83.4 91.8 81.1 71.0 . . .
63 772 706 799 82.8 91.4 80.1 69.9 . . .
62 746 688 776 82.3 91.1 79.3 68.8 . . .
61 720 670 754 81.8 90.7 78.4 67.7 . . .
60 697 654 732 81.2 90.2 77.5 66.6 . . .
59 674 634 710 80.7 89.8 76.6 65.5 351 (2420)
58 653 615 690 80.1 89.3 75.7 64.3 338 (2330)
57 633 595 670 79.6 88.9 74.8 63.2 325 (2240)
56 613 577 650 79.0 88.3 73.9 62.0 313 (2160)
55 595 560 630 78.5 87.9 73.0 60.9 301 (2070)
54 577 543 612 78.0 87.4 72.0 59.8 292 (2010)
53 560 525 594 77.4 86.9 71.2 58.6 283 (1950)
52 544 512 576 76.8 86.4 70.2 57.4 273 (1880)
51 528 496 558 76.3 85.9 69.4 56.1 264 (1820)
50 513 482 542 75.9 85.5 68.5 55.0 255 (1760)
49 498 468 526 75.2 85.0 67.6 53.8 246 (1700)
48 484 455 510 74.7 84.5 66.7 52.5 238 (1640)
47 471 442 495 74.1 83.9 65.8 51.4 229 (1580)
46 458 432 480 73.6 83.5 64.8 50.3 221 (1520)
45 446 421 466 73.1 83.0 64.0 49.0 215 (1480)
44 434 409 452 72.5 82.5 63.1 47.8 208 (1430)
43 423 400 438 72.0 82.0 62.2 46.7 201 (1390)
42 412 390 426 71.5 81.5 61.3 45.5 194 (1340)
41 402 381 414 70.9 80.9 60.4 44.3 188 (1300)
40 392 371 402 70.4 80.4 59.5 43.1 182 (1250)
39 382 362 391 69.9 79.9 58.6 41.9 177 (1220)
38 372 353 380 69.4 79.4 57.7 40.8 171 (1180)
37 363 344 370 68.9 78.8 56.8 39.6 166 (1140)
36 354 336 360 68.4 78.3 55.9 38.4 161 (1110)
35 345 327 351 67.9 77.7 55.0 37.2 156 (1080)
34 336 319 342 67.4 77.2 54.2 36.1 152 (1050)
33 327 311 334 66.8 76.6 53.3 34.9 149 (1030)
32 318 301 326 66.3 76.1 52.1 33.7 146 (1010)
31 310 294 318 65.8 75.6 51.3 32.5 141 (970)
30 302 286 311 65.3 75.0 50.4 31.3 138 (950)
29 294 279 304 64.6 74.5 49.5 30.1 135 (930)
28 286 271 297 64.3 73.9 48.6 28.9 131 (900)
27 279 264 290 63.8 73.3 47.7 27.8 128 (880)
26 272 258 284 63.3 72.8 46.8 26.7 125 (860)
25 266 253 278 62.8 72.2 45.9 25.5 123 (850)
24 260 247 272 62.4 71.6 45.0 24.3 119 (820)
23 254 243 266 62.0 71.0 44.0 23.1 117 (810)
22 248 237 261 61.5 70.5 43.2 22.0 115 (790)
21 243 231 256 61.0 69.9 42.3 20.7 112 (770)
20 238 226 251 60.5 69.4 41.5 19.6 110 (760)
A This table gives the approximate interrelationships of hardness values and approximate tensile strength of steels. It is possible that steels of various compositions and
processing histories will deviate in hardness-tensile strength relationship from the data presented in this table. The data in this table should not be used for austenitic
stainless steels, but have been shown to be applicable for ferritic and martensitic stainless steels. The data in this table should not be used to establish a relationship
between hardness values and tensile strength of hard drawn wire. Where more precise conversions are required, they should be developed specially for each steel
composition, heat treatment, and part.
A 370 – 03a
12Copyright ASTM International 
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Not for ResaleNo reproduction or networking permitted without license from IHS
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TABLE 3 Approximate Hardness Conversion Numbers for Nonaustenitic Steels A (Rockwell B to Other Hardness Numbers)
Rockwell B
Scale, 100-
kgf Load 1⁄16-
in. (1.588-
mm)
BallVickers
Hardness
Number
Brinell
Hardness,
3000-kgf Load,
10-mm Ball
Knoop
Hardness,
500-gf Load
and Over
Rockwell A
Scale,
60-kgf
Load, Diamond
Penetrator
Rockwell F
Scale,
60-kgf
Load, 1⁄16-in.
(1.588-mm) Ball
Rockwell Superficial Hardness
Approximate
Tensile
Strength
ksi (MPa)
15T Scale,
15-kgf
Load,
1⁄16 -in.
(1.588-
mm) Ball
30T Scale,
30-kgf
Load,
1⁄16-in.
(1.588-
mm) Ball
45T Scale,
45-kgf
Load,
1⁄16-in.
(1.588-
mm) Ball
100 240 240 251 61.5 . . . 93.1 83.1 72.9 116 (800)
99 234 234 246 60.9 . . . 92.8 82.5 71.9 114 (785)
98 228 228 241 60.2 . . . 92.5 81.8 70.9 109 (750)
97 222 222 236 59.5 . . . 92.1 81.1 69.9 104 (715)
96 216 216 231 58.9 . . . 91.8 80.4 68.9 102 (705)
95 210 210 226 58.3 . . . 91.5 79.8 67.9 100 (690)
94 205 205 221 57.6 . . . 91.2 79.1 66.9 98 (675)
93 200 200 216 57.0 . . . 90.8 78.4 65.9 94 (650)
92 195 195 211 56.4 . . . 90.5 77.8 64.8 92 (635)
91 190 190 206 55.8 . . . 90.2 77.1 63.8 90 (620)
90 185 185 201 55.2 . . . 89.9 76.4 62.8 89 (615)
89 180 180 196 54.6 . . . 89.5 75.8 61.8 88 (605)
88 176 176 192 54.0 . . . 89.2 75.1 60.8 86 (590)
87 172 172 188 53.4 . . . 88.9 74.4 59.8 84 (580)
86 169 169 184 52.8 . . . 88.6 73.8 58.8 83 (570)
85 165 165 180 52.3 . . . 88.2 73.1 57.8 82 (565)
84 162 162 176 51.7 . . . 87.9 72.4 56.8 81 (560)
83 159 159 173 51.1 . . . 87.6 71.8 55.8 80 (550)
82 156 156 170 50.6 . . . 87.3 71.1 54.8 77 (530)
81 153 153 167 50.0 . . . 86.9 70.4 53.8 73 (505)
80 150 150 164 49.5 . . . 86.6 69.7 52.8 72 (495)
79 147 147 161 48.9 . . . 86.3 69.1 51.8 70 (485)
78 144 144 158 48.4 . . . 86.0 68.4 50.8 69 (475)
77 141 141 155 47.9 . . . 85.6 67.7 49.8 68 (470)
76 139 139 152 47.3 . . . 85.3 67.1 48.8 67 (460)
75 137 137 150 46.8 99.6 85.0 66.4 47.8 66 (455)
74 135 135 147 46.3 99.1 84.7 65.7 46.8 65 (450)
73 132 132 145 45.8 98.5 84.3 65.1 45.8 64 (440)
72 130 130 143 45.3 98.0 84.0 64.4 44.8 63 (435)
71 127 127 141 44.8 97.4 83.7 63.7 43.8 62 (425)
70 125 125 139 44.3 96.8 83.4 63.1 42.8 61 (420)
69 123 123 137 43.8 96.2 83.0 62.4 41.8 60 (415)
68 121 121 135 43.3 95.6 82.7 61.7 40.8 59 (405)
67 119 119 133 42.8 95.1 82.4 61.0 39.8 58 (400)
66 117 117 131 42.3 94.5 82.1 60.4 38.7 57 (395)
65 116 116 129 41.8 93.9 81.8 59.7 37.7 56 (385)
64 114 114 127 41.4 93.4 81.4 59.0 36.7 . . .
63 112 112 125 40.9 92.8 81.1 58.4 35.7 . . .
62 110 110 124 40.4 92.2 80.8 57.7 34.7 . . .
61 108 108 122 40.0 91.7 80.5 57.0 33.7 . . .
60 107 107 120 39.5 91.1 80.1 56.4 32.7 . . .
59 106 106 118 39.0 90.5 79.8 55.7 31.7 . . .
58 104 104 117 38.6 90.0 79.5 55.0 30.7 . . .
57 103 103 115 38.1 89.4 79.2 54.4 29.7 . . .
56 101 101 114 37.7 88.8 78.8 53.7 28.7 . . .
55 100 100 112 37.2 88.2 78.5 53.0 27.7 . . .
54 . . . . . . 111 36.8 87.7 78.2 52.4 26.7 . . .
53 . . . . . . 110 36.3 87.1 77.9 51.7 25.7 . . .
52 . . . . . . 109 35.9 86.5 77.5 51.0 24.7 . . .
51 . . . . . . 108 35.5 86.0 77.2 50.3 23.7 . . .
50 . . . . . . 107 35.0 85.4 76.9 49.7 22.7 . . .
49 . . . . . . 106 34.6 84.8 76.6 49.0 21.7 . . .
48 . . . . . . 105 34.1 84.3 76.2 48.3 20.7 . . .
47 . . . . . . 104 33.7 83.7 75.9 47.7 19.7 . . .
46 . . . . . . 103 33.3 83.1 75.6 47.0 18.7 . . .
45 . . . . . . 102 32.9 82.6 75.3 46.3 17.7 . . .
44 . . . . . . 101 32.4 82.0 74.9 45.7 16.7 . . .
43 . . . . . . 100 32.0 81.4 74.6 45.0 15.7 . . .
42 . . . . . . 99 31.6 80.8 74.3 44.3 14.7 . . .
41 . . . . . . 98 31.2 80.3 74.0 43.7 13.6 . . .
40 . . . . . . 97 30.7 79.7 73.6 43.0 12.6 . . .
39 . . . . . . 96 30.3 79.1 73.3 42.3 11.6 . . .
38 . . . . . . 95 29.9 78.6 73.0 41.6 10.6 . . .
37 . . . . . . 94 29.5 78.0 72.7 41.0 9.6 . . .
36 . . . . . . 93 29.1 77.4 72.3 40.3 8.6 . . .
35 . . . . . . 92 28.7 76.9 72.0 39.6 7.6 . . .
34 . . . . . . 91 28.2 76.3 71.7 39.0 6.6 . . .
33 . . . . . . 90 27.8 75.7 71.4 38.3 5.6 . . .
A 370 – 03a
13Copyright ASTM International 
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16.4.3 Measure two diameters of the indentation at right
angles to the nearest 0.1 mm, estimate to the nearest 0.05 mm,
and average to the nearest 0.05 mm. If the two diameters differ
by more than 0.1 mm, discard the readings and make a new
indentation.
16.4.4 Do not use a steel ball on steels having a hardness
over 450 HB nor a carbide ball on steels having a hardness over
650 HB. The Brinell hardness test is not recommended for
materials having a hardness over 650 HB.
16.4.4.1 If a ball is used in a test of a specimen which shows
a Brinell hardness number greater than the limit for the ball as
detailed in 16.4.4, the ball shall be either discarded and
replaced with a new ball or remeasured to ensure conformance
with the requirements of Test Method E 10.
16.5 Detailed Procedure—For detailed requirements of this
test, reference shall be made to the latest revision of Test
Method E 10.
TABLE 3 Continued
Rockwell B
Scale, 100-
kgf Load 1⁄16-
in. (1.588-
mm)
Ball
Vickers
Hardness
Number
Brinell
Hardness,
3000-kgf Load,
10-mm Ball
Knoop
Hardness,
500-gf Load
and Over
Rockwell A
Scale,
60-kgf
Load, Diamond
Penetrator
Rockwell F
Scale,
60-kgf
Load, 1⁄16-in.
(1.588-mm) Ball
Rockwell Superficial Hardness
Approximate
Tensile
Strength
ksi (MPa)
15T Scale,
15-kgf
Load,
1⁄16 -in.
(1.588-
mm) Ball
30T Scale,
30-kgf
Load,
1⁄16-in.
(1.588-
mm) Ball
45T Scale,
45-kgf
Load,
1⁄16-in.
(1.588-
mm) Ball
32 . . . . . . 89 27.4 75.2 71.0 37.6 4.6 . . .
31 . . . . . . 88 27.0 74.6 70.7 37.0 3.6 . . .
30 . . . . . . 87 26.6 74.0 70.4 36.3 2.6 . . .
A This table gives the approximate interrelationships of hardness values and approximate tensile strength of steels. It is possible that steels of various compositions and
processing histories will deviate in hardness-tensile strength relationship from the data presented in this table. The data in this table should not be used for austenitic
stainless steels, but have been shown to be applicable for ferritic and martensitic stainless steels. The data in this table should not be used to establish a relationship
between hardness values and tensile strength of hard drawn wire. Where more precise conversions are required, they should be developed specially for each steel
composition, heat treatment, and part.
TABLE 4 Approximate Hardness Conversion Numbers for Austenitic Steels (Rockwell C to other Hardness Numbers)
Rockwell C Scale, 150-kgf
Load, Diamond Penetrator
Rockwell A Scale, 60-kgf
Load, Diamond Penetrator
Rockwell Superficial Hardness
15N Scale, 15-kgf Load,
Diamond Penetrator
30N Scale, 30-kgf Load,
Diamond Penetrator
45N Scale, 45-kgf Load,
Diamond Penetrator
48 74.4 84.1 66.2 52.1
47 73.9 83.6 65.3 50.9
46 73.4 83.1 64.5 49.8
45 72.9 82.6 63.6 48.7
44 72.4 82.1 62.7 47.5
43 71.9 81.6 61.8 46.4
42 71.4 81.0 61.0 45.2
41 70.9 80.5 60.1 44.1
40 70.4 80.0 59.2 43.0
39 69.9 79.5 58.4 41.8
38 69.3 79.0 57.5 40.7
37 68.8 78.5 56.6 39.6
36 68.3 78.0 55.7 38.4
35 67.8 77.5 54.9 37.3
34 67.3 77.0 54.0 36.1
33 66.8 76.5 53.1 35.0
32 66.3 75.9 52.3 33.9
31 65.8 75.4 51.4 32.7
30 65.3 74.9 50.5 31.6
29 64.8 74.4 49.6 30.4
28 64.3 73.9 48.8 29.3
27 63.8 73.4 47.9 28.2
26 63.3 72.9 47.0 27.0
25 62.8 72.4 46.2 25.9
24 62.3 71.9 45.3 24.8
23 61.8 71.3 44.4 23.6
22 61.3 70.8 43.5 22.5
21 60.8 70.3 42.7 21.3
20 60.3 69.8 41.8 20.2
A 370 – 03a
14Copyright ASTM International 
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Not for ResaleNo reproduction or networking permitted without license from IHS
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TABLE 6 Brinell Hardness Numbers A
(Ball 10 mm in Diameter, Applied Loads of 500, 1500, and 3000 kgf)
Diameter
of Indenta-
tion, mm
Brinell Hardness Number
Diameter
of Indenta-
tion, mm
Brinell Hardness Number Diameter
of Indenta-
tion, mm
Brinell Hardness Number
Diameter
of Indenta-
tion, mm
Brinell Hardness Number
500-
kgf
Load
1500-
kgf
Load
3000-
kgf
Load
500-
kgf
Load
1500-
kgf
Load
3000-
kgf
Load
500-
kgf
Load
1500-
kgf
Load
3000-
kgf
Load
500-
kgf
Load
1500-
kgf
Load
3000-kgf
Load
2.00 158 473 945 2.60 92.6 278 555 3.20 60.5 182 363 3.80 42.4 127 255
2.01 156 468 936 2.61 91.8 276 551 3.21 60.1 180 361 3.81 42.2 127 253
2.02 154 463 926 2.62 91.1 273 547 3.22 59.8 179 359 3.82 42.0 126 252
2.03 153 459 917 2.63 90.4 271 543 3.23 59.4 178 356 3.83 41.7 125 250
2.04 151 454 908 2.64 89.7 269 538 3.24 59.0 177 354 3.84 41.5 125 249
2.05 150 450 899 2.65 89.0 267 534 3.25 58.6 176 352 3.85 41.3 124 248
2.06 148 445 890 2.66 88.4 265 530 3.26 58.3 175 350 3.86 41.1 123 246
2.07 147 441 882 2.67 87.7 263 526 3.27 57.9 174 347 3.87 40.9 123 245
2.08 146 437 873 2.68 87.0 261 522 3.28 57.5 173 345 3.88 40.6 122 244
2.09 144 432 865 2.69 86.4 259 518 3.29 57.2 172 343 3.89 40.4 121 242
2.10 143 428 856 2.70 85.7 257 514 3.30 56.8 170 341 3.90 40.2 121 241
2.11 141 424 848 2.71 85.1 255 510 3.31 56.5 169 339 3.91 40.0 120 240
2.12 140 420 840 2.72 84.4 253 507 3.32 56.1 168 337 3.92 39.8 119 239
2.13 139 416 832 2.73 83.8 251 503 3.33 55.8 167 335 3.93 39.6 119 237
2.14 137 412 824 2.74 83.2 250 499 3.34 55.4 166 333 3.94 39.4 118 236
2.15 136 408 817 2.75 82.6 248 495 3.35 55.1 165 331 3.95 39.1 117 235
2.16 135 404 809 2.76 81.9 246 492 3.36 54.8 164 329 3.96 38.9 117 234
2.17 134 401 802 2.77 81.3 244 488 3.37 54.4 163 326 3.97 38.7 116 232
2.18 132 397 794 2.78 80.8 242 485 3.38 54.1 162 325 3.98 38.5 116 231
2.19 131 393 787 2.79 80.2 240 481 3.39 53.8 161 323 3.99 38.3 115 230
2.20 130 390 780 2.80 79.6 239 477 3.40 53.4 160 321 4.00 38.1 114 229
2.21 129 386 772 2.81 79.0 237 474 3.41 53.1 159 319 4.01 37.9 114 228
2.22 128 383 765 2.82 78.4 235 471 3.42 52.8 158 317 4.02 37.7 113 226
2.23 126 379 758 2.83 77.9 234 467 3.43 52.5 157 315 4.03 37.5 113 225
2.24 125 376 752 2.84 77.3 232 464 344 52.2 156 313 4.04 37.3 112 224
2.25 124 372 745 2.85 76.8 230 461 3.45 51.8 156 311 4.05 37.1 111 223
2.26 123 369 738 2.86 76.2 229 457 3.46 51.5 155 309 4.06 37.0 111 222
2.27 122 366 732 2.87 75.7 227 454 3.47 51.2 154 307 4.07 36.8 110 221
2.28 121 363 725 2.88 75.1 225 451 3.48 50.9 153 306 4.08 36.6 110 219
2.29 120 359 719 2.89 74.6 224 448 3.49 50.6 152 304 4.09 36.4 109 218
2.30 119 356 712 2.90 74.1 222 444 3.50 50.3 151 302 4.10 36.2 109 217
2.31 118 353 706 2.91 73.6 221 441 3.51 50.0 150 300 4.11 36.0 108 216
2.32 117 350 700 2.92 73.0 219 438 3.52 49.7 149 298 4.12 35.8 108 215
2.33 116 347 694 2.93 72.5 218 435 3.53 49.4 148 297 4.13 35.7 107 214
2.34 115 344 688 2.94 72.0 216 432 3.54 49.2 147 295 4.14 35.5 106 213
2.35 114 341 682 2.95 71.5 215 429 3.55 48.9 147 293 4.15 35.3 106 212
2.36 113 338 676 2.96 71.0 213 426 3.56 48.6 146 292 4.16 35.1 105 211
2.37 112 335 670 2.97 70.5 212 423 3.57 48.3 145 290 4.17 34.9 105 210
TABLE 5 Approximate Hardness Conversion Numbers for Austenitic Steels (Rockwell B to other Hardness Numbers)
Rockwell B
Scale, 100-
kgf Load, 1⁄16-
in. (1.588-
mm) Ball
Brinell Indentation
Diameter, mm
Brinell Hardness,
3000-kgf Load,
10-mm Ball
Rockwell A Scale,
60-kgf Load,
Diamond Penetrator
Rockwell Superficial Hardness
15T Scale,
15-kgf Load,
1⁄16-in. (1.588-
mm) Ball
30T Scale,
30-kgf Load,
1⁄16-in. (1.588-
mm) Ball
45T Scale,
45-kgf Load,
1⁄16-in. (1.588-
mm) Ball
100 3.79 256 61.5 91.5 80.4 70.2
99 3.85 248 60.9 91.2 79.7 69.2
98 3.91 240 60.3 90.8 79.0 68.2
97 3.96 233 59.7 90.4 78.3 67.2
96 4.02 226 59.1 90.1 77.7 66.1
95 4.08 219 58.5 89.7 77.0 65.1
94 4.14 213 58.0 89.3 76.3 64.1
93 4.20 207 57.4 88.9 75.6 63.1
92 4.24 202 56.8 88.6 74.9 62.1
91 4.30 197 56.2 88.2 74.2 61.1
90 4.35 192 55.6 87.8 73.5 60.1
89 4.40 187 55.0 87.5 72.8 59.0
88 4.45 183 54.5 87.1 72.1 58.0
87 4.51 178 53.9 86.7 71.4 57.0
86 4.55 174 53.3 86.4 70.7 56.0
85 4.60 170 52.7 86.0 70.0 55.0
84 4.65 167 52.1 85.6 69.3 54.0
83 4.70 163 51.5 85.2 68.6 52.9
82 4.74 160 50.9 84.9 67.9 51.9
81 4.79 156 50.4 84.5 67.2 50.9
80 4.84 153 49.8 84.1 66.5 49.9
A 370 – 03a
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TABLE 6 Continued
Diameter
of Indenta-
tion, mm
Brinell Hardness Number
Diameter
of Indenta-
tion, mm
Brinell Hardness Number Diameter
of Indenta-
tion, mm
Brinell Hardness Number
Diameter
of Indenta-
tion, mm
Brinell Hardness Number
500-
kgf
Load
1500-
kgf
Load
3000-
kgf
Load
500-
kgf
Load
1500-
kgf
Load
3000-
kgf
Load
500-
kgf
Load
1500-
kgf
Load
3000-
kgf
Load
500-
kgf
Load
1500-
kgf
Load
3000-
kgf
Load
2.38 111 332 665 2.98 70.1 210 420 3.58 48.0 144 288 4.18 34.8 104 209
2.39 110 330 659 2.99 69.6 209 417 3.59 47.7 143 286 4.19 34.6 104 208
2.40 109 327 653 3.00 69.1 207 415 3.60 47.5 142 285 4.20 34.4 103 207
2.41 108 324 648 3.01 68.6 206 412 3.61 47.2 142 283 4.21 34.2 103 205
2.42 107 322 643 3.02 68.2 205 409 3.62 46.9 141 282 4.22 34.1 102 204
2.43 106 319 637 3.03 67.7 203 406 3.63 46.7 140 280 4.23 33.9 102 203
2.44 105 316 632 3.04 67.3 202 404 3.64 46.4 139 278 4.24 33.7 101 202
2.45 104 313 627 3.05 66.8 200 401 3.65 46.1 138 277 4.25 33.6 101 201
2.46 104 311 621 3.06 66.4 199 398 3.66 45.9 138 275 4.26 33.4 100 200
2.47 103 308 616 3.07 65.9 198 395 3.67 45.6 137 274 4.27 33.2 99.7 199
2.48 102 306 611 3.08 65.5 196 393 3.68 45.4 136 272 4.28 33.1 99.2 198
2.49 101 303 606 3.09 65.0 195 390 3.69 45.1 135 271 4.29 32.9 98.8 198
2.50 100 301 601 3.10 64.6 194 388 3.70 44.9 135 269 4.30 32.8 98.3 197
2.51 99.4 298 597 3.11 64.2 193 385 3.71 44.6 134 268 4.31 32.6 97.8 196
2.52 98.6 296 592 3.12 63.8 191 383 3.72 44.4 133 266 4.32 32.4 97.3 195
2.53 97.8 294 587 3.13 63.3 190 380 3.73 44.1 132 265 4.33 32.3 96.8 194
2.54 97.1 291 582 3.14 62.9 189 378 3.74 43.9 132 263 4.34 32.1 96.4 193
2.55 96.3 289 578 3.15 62.5 188 375 3.75 43.6 131 262 4.35 32.0 95.9 192
2.56 95.5 287 573 3.16 62.1 186 373 3.76 43.4 130 260 4.36 31.8 95.5 191
2.57 94.8 284 569 3.17 61.7 185 370 3.77 43.1 129 259 4.37 31.7 95.0 190
2.58 94.0 282 564 3.18 61.3 184 368 3.78 42.9 129 257 4.38 31.5 94.5 189
2.59 93.3 280 560 3.19 60.9 183 366 3.79 42.7 128 256 4.39 31.4 94.1 188
A 370 – 03a
16Copyright ASTM International 
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TABLE 6 Continued
Diameter
of Indenta-
tion, mm
Brinell Hardness Number
Diameter
of Indenta-
tion, mm
Brinell Hardness Number Diameter
of Indenta-
tion, mm
Brinell Hardness Number
Diameter
of Indenta-
tion, mm
Brinell Hardness Number
500-
kgf
Load
1500-
kgf
Load
3000-
kgf
Load
500-
kgf
Load
1500-
kgf
Load
3000-
kgf
Load
500-
kgf
Load
1500-
kgf
Load
3000-
kgf
Load
500-
kgf
Load
1500-
kgf
Load
3000-
kgf
Load
4.40 31.2 93.6 187 5.05 23.3 69.8 140 5.70 17.8 53.5 107 6.35 14.0 42.0 84.0
4.41 31.1 93.2 186 5.06 23.2 69.5 139 5.71 17.8 53.3 107 6.36 13.9 41.8 83.7
4.42 30.9 92.7 185 5.07 23.1 69.2 138 5.72 17.7 53.1 106 6.37 13.9 41.7 83.4
4.43 30.8 92.3 185 5.08 23.0 68.9 138 5.73 17.6 52.9 106 6.38 13.8 41.5 83.1
4.44 30.6 91.8 184 5.09 22.9 68.6 137 5.74 17.6 52.7 105 6.39 13.8 41.4 82.8
4.45 30.5 91.4 183 5.10 22.8 68.3 137 5.75 17.5 52.5 105 6.40 13.7 41.2 82.5
4.46 30.3 91.0 182 5.11 22.7 68.0 136 5.76 17.4 52.3 105 6.41 13.7 41.1 82.2
4.47 30.2 90.5 181 5.12 22.6 67.7 135 5.77 17.4 52.1 104 6.42 13.6 40.9 81.9
4.48 30.0 90.1 180 5.13 22.5 67.4 135 5.78 17.3 51.9 104 6.43 13.6 40.8 81.6
4.49 29.9 89.7 179 5.14 22.4 67.1 134 5.79 17.2 51.7 103 6.44 13.5 40.6 81.3
4.50 29.8 89.3 179 5.15 22.3 66.9 134 5.80 17.2 51.5 103 6.45 13.5 40.5 81.0
4.51 29.6 88.8 178 5.16 22.2 66.6 133 5.81 17.1 51.3 103 6.46 13.4 40.4 80.7
4.52 29.5 88.4 177 5.17 22.1 66.3 133 5.82 17.0 51.1 102 6.47 13.4 40.2 80.4
4.53 29.3 88.0 176 5.18 22.0 66.0 132 5.83 17.0 50.9 102 6.48 13.4 40.1 80.1
4.54 29.2 87.6 175 5.19 21.9 65.8 132 5.84 16.9 50.7 101 6.49 13.3 39.9 79.8
4.55 29.1 87.2 174 5.20 21.8 65.5 131 5.85 16.8 50.5 101 6.50 13.3 39.8 79.6
4.56 28.9 86.8 174 5.21 21.7 65.2 130 5.86 16.8 50.3101 6.51 13.2 39.6 79.3
4.57 28.8 86.4 173 5.22 21.6 64.9 130 5.87 16.7 50.2 100 6.52 13.2 39.5 79.0
4.58 28.7 86.0 172 5.23 21.6 64.7 129 5.88 16.7 50.0 99.9 6.53 13.1 39.4 78.7
4.59 28.5 85.6 171 5.24 21.5 64.4 129 5.89 16.6 49.8 99.5 6.54 13.1 39.2 78.4
4.60 28.4 85.4 170 5.25 21.4 64.1 128 5.90 16.5 49.6 99.2 6.55 13.0 39.1 78.2
4.61 28.3 84.8 170 5.26 21.3 63.9 128 5.91 16.5 49.4 98.8 6.56 13.0 38.9 78.0
4.62 28.1 84.4 169 5.27 21.2 63.6 127 5.92 16.4 49.2 98.4 6.57 12.9 38.8 77.6
4.63 28.0 84.0 168 5.28 21.1 63.3 127 5.93 16.3 49.0 98.0 6.58 12.9 38.7 77.3
4.64 27.9 83.6 167 5.29 21.0 63.1 126 5.94 16.3 48.8 97.7 6.59 12.8 38.5 77.1
4.65 27.8 83.3 167 5.30 20.9 62.8 126 5.95 16.2 48.7 97.3 6.60 12.8 38.4 76.8
4.66 27.6 82.9 166 5.31 20.9 62.6 125 5.96 16.2 48.5 96.9 6.61 12.8 38.3 76.5
4.67 27.5 82.5 165 5.32 20.8 62.3 125 5.97 16.1 48.3 96.6 6.62 12.7 38.1 76.2
4.68 27.4 82.1 164 5.33 20.7 62.1 124 5.98 16.0 48.1 96.2 6.63 12.7 38.0 76.0
4.69 27.3 81.8 164 5.34 20.6 61.8 124 5.99 16.0 47.9 95.9 6.64 12.6 37.9 75.7
4.70 27.1 81.4 163 5.35 20.5 61.5 123 6.00 15.9 47.7 95.5 6.65 12.6 37.7 75.4
4.71 27.0 81.0 162 5.36 20.4 61.3 123 6.01 15.9 47.6 95.1 6.66 12.5 37.6 75.2
4.72 26.9 80.7 161 5.37 20.3 61.0 122 6.02 15.8 47.4 94.8 6.67 12.5 37.5 74.9
4.73 26.8 80.3 161 5.38 20.3 60.8 122 6.03 15.7 47.2 94.4 6.68 12.4 37.3 74.7
4.74 26.6 79.9 160 5.39 20.2 60.6 121 6.04 15.7 47.0 94.1 6.69 12.4 37.2 74.4
4.75 26.5 79.6 159 5.40 20.1 60.3 121 6.05 15.6 46.8 93.7 6.70 12.4 37.1 74.1
4.76 26.4 79.2 158 5.41 20.0 60.1 120 6.06 15.6 46.7 93.4 6.71 12.3 36.9 73.9
4.77 26.3 78.9 158 5.42 19.9 59.8 120 6.07 15.5 46.5 93.0 6.72 12.3 36.8 73.6
4.78 26.2 78.5 157 5.43 19.9 59.6 119 6.08 15.4 46.3 92.7 6.73 12.2 36.7 73.4
4.79 26.1 78.2 156 5.44 19.8 59.3 119 6.09 15.4 46.2 92.3 6.74 12.2 36.6 73.1
4.80 25.9 77.8 156 5.45 19.7 59.1 118 6.10 15.3 46.0 92.0 6.75 12.1 36.4 72.8
4.81 25.8 77.5 155 5.46 19.6 58.9 118 6.11 15.3 45.8 91.7 6.76 12.1 36.3 72.6
4.82 25.7 77.1 154 5.47 19.5 58.6 117 6.12 15.2 45.7 91.3 6.77 12.1 36.2 72.3
4.83 25.6 76.8 154 5.48 19.5 58.4 117 6.13 15.2 45.5 91.0 6.78 12.0 36.0 72.1
4.84 25.5 76.4 153 5.49 19.4 58.2 116 6.14 15.1 45.3 90.6 6.79 12.0 35.9 71.8
4.85 25.4 76.1 152 5.50 19.3 57.9 116 6.15 15.1 45.2 90.3 6.80 11.9 35.8 71.6
4.86 25.3 75.8 152 5.51 19.2 57.7 115 6.16 15.0 45.0 90.0 6.81 11.9 35.7 71.3
4.87 25.1 75.4 151 5.52 19.2 57.5 115 6.17 14.9 44.8 89.6 6.82 11.8 35.5 71.1
4.88 25.0 75.1 150 5.53 19.1 57.2 114 6.18 14.9 44.7 89.3 6.83 11.8 35.4 70.8
4.89 24.9 74.8 150 5.54 19.0 57.0 114 6.19 14.8 44.5 89.0 6.84 11.8 35.3 70.6
4.90 24.8 74.4 149 5.55 18.9 56.8 114 6.20 14.7 44.3 88.7 6.86 11.7 35.2 70.4
4.91 24.7 74.1 148 5.56 18.9 56.6 113 6.21 14.7 44.2 88.3 6.86 11.7 35.1 70.1
4.92 24.6 73.8 148 5.57 18.8 56.3 113 6.22 14.7 44.0 88.0 6.87 11.6 34.9 69.9
4.93 24.5 73.5 147 5.58 18.7 56.1 112 6.23 14.6 43.8 87.7 6.88 11.6 34.8 69.6
4.94 24.4 73.2 146 5.59 18.6 55.9 112 6.24 14.6 43.7 87.4 6.89 11.6 34.7 69.4
4.95 24.3 72.8 146 5.60 18.6 55.7 111 6.25 14.5 43.5 87.1 6.90 11.5 34.6 69.2
4.96 24.2 72.5 145 5.61 18.5 55.5 111 6.26 14.5 43.4 86.7 6.91 11.5 34.5 68.9
4.97 24.1 72.2 144 5.62 18.4 55.2 110 6.27 14.4 43.2 86.4 6.92 11.4 34.3 68.7
4.98 24.0 71.9 144 5.63 18.3 55.0 110 6.28 14.4 43.1 86.1 6.93 11.4 34.2 68.4
4.99 23.9 71.6 143 5.64 18.3 54.8 110 6.29 14.3 42.9 85.8 6.94 11.4 34.1 68.2
5.00 23.8 71.3 143 5.65 18.2 54.6 109 6.30 14.2 42.7 85.5 6.95 11.3 34.0 68.0
5.01 23.7 71.0 142 5.66 18.1 54.4 109 6.31 14.2 42.6 85.2 6.96 11.3 33.9 67.7
5.02 23.6 70.7 141 5.67 18.1 54.2 108 6.32 14.1 42.4 84.9 6.97 11.3 33.8 67.5
5.03 23.5 70.4 141 5.68 18.0 54.0 108 6.33 14.1 42.3 84.6 6.98 11.2 33.6 67.3
5.04 23.4 70.1 140 5.69 17.9 53.7 107 6.34 14.0 42.1 84.3 6.99 11.2 33.5 67.0
A Prepared by the Engineering Mechanics Section, Institute for Standards Technology.
A 370 – 03a
17Copyright ASTM International 
Provided by IHS under license with ASTM
Not for ResaleNo reproduction or networking permitted without license from IHS
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17. Rockwell Test
17.1 Description:
17.1.1 In this test a hardness value is obtained by determin-
ing the depth of penetration of a diamond point or a steel ball
into the specimen under certain arbitrarily fixed conditions. A
minor load of 10 kgf is first applied which causes an initial
penetration, sets the penetrator on the material and holds it in
position. A major load which depends on the scale being used
is applied increasing the depth of indentation. The major load
is removed and, with the minor load still acting, the Rockwell
number, which is proportional to the difference in penetration
between the major and minor loads is determined; this is
usually done by the machine and shows on a dial, digital
display, printer, or other device. This is an arbitrary number
which increases with increasing hardness. The scales most
frequently used are as follows:
Scale
Symbol Penetrator
Major
Load,
kgf
Minor
Load,
kgf
B 1⁄16-in. steel ball 100 10
C Diamond brale 150 10
17.1.2 Rockwell superficial hardness machines are used for
the testing of very thin steel or thin surface layers. Loads of 15,
30, or 45 kgf are applied on a hardened steel ball or diamond
penetrator, to cover the same range of hardness values as for
the heavier loads. The superficial hardness scales are as
follows:
Major Minor
Scale Load, Load,
Symbol Penetrator kgf kgf
15T 1⁄16-in. steel ball 15 3
30T 1⁄16-in. steel ball 30 3
45T 1⁄16-in. steel ball 45 3
15N Diamond brale 15 3
30N Diamond brale 30 3
45N Diamond brale 45 3
17.2 Reporting Hardness—In recording hardness values,
the hardness number shall always precede the scale symbol, for
example: 96 HRB, 40 HRC, 75 HR15N, or 77 HR30T.
17.3 Test Blocks—Machines should be checked to make
certain they are in good order by means of standardized
Rockwell test blocks.
17.4 Detailed Procedure—For detailed requirements of this
test, reference shall be made to the latest revision of Test
Methods E 18.
18. Portable Hardness Test
18.1 Although the use of the standard, stationary Brinell or
Rockwell hardness tester is generally preferred, it is not always
possible to perform the hardness test using such equipment due
to the part size or location. In this event, hardness testing using
portable equipment as described in Practice A 833 or Test
Method E 110 shall be used.
CHARPY IMPACT TESTING
19. Summary
19.1 A Charpy V-notch impact test is a dynamic test in
which a notched specimen is struck and broken by a single
blow in a specially designed testing machine. The measured
test values may be the energy absorbed, the percentage shear
fracture, the lateral expansion opposite the notch, or a combi-
nation thereof.
19.2 Testing temperatures other than room (ambient) tem-
perature often are specified in product or general requirement
specifications (hereinafter referred to as the specification).
Although the testing temperature is sometimes related to the
expected service temperature, the two temperatures need not be
identical.
20. Significance and Use
20.1 Ductile vs. Brittle Behavior—Body-centered-cubic or
ferritic alloys exhibit a significant transition in behavior when
impact tested over a range of temperatures. At temperatures
above transition, impact specimens fracture by a ductile
(usually microvoid coalescence) mechanism, absorbing rela-
tively large amounts of energy. At lower temperatures, they
fracture in a brittle (usually cleavage) manner absorbing less
energy. Within the transition range, the fracture will generally
be a mixture of areas of ductile fracture and brittle fracture.
20.2 The temperature range of the transition from one type
of behavior to the other varies according to the material being
tested. This transition behavior may be defined in various ways
for specification purposes.
20.2.1 The specification may require a minimum test result
for absorbed energy, fracture appearance, lateral expansion, or
a combination thereof, at a specified test temperature.
20.2.2 The specification