ASTM A304-96

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
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Designation: A 304 – 96 An American National Standard
Standard Specification for
Carbon and Alloy Steel Bars Subject to End-Quench
Hardenability Requirements
This standard is issued under the fixed designation A 304; 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 4. Ordering Information
1.1 This specification covers hot-worked alloy, carbon, and 4.1 Orders for material under this specification should
carbon-boron steels in a variety of compositions and sizes include the following information, in proper sequence:
which may attain specified depth of hardening in the end 4.1.1 Quantity (weight),
quench test. These steel compositions are identified by the 4.1.2 Name of material (alloy, carbon, or carbon-boron
suffix letter “H” added to the conventional grade number. steel),
1.2 This specification provides for analyses other than those 4.1.3 Cross-sectional shape,
listed under Table 1 and Table 2. Special hardenability limits 4.1.4 Size,
are also permissible when approved by the purchaser and 4.1.5 Length,
manufacturer. 4.1.6 Grade,
1.3 The values stated in inch-pound units are to be regarded 4.1.7 End-quenched hardenability (see Section 9),
as the standard. 4.1.8 Report of heat analysis, if desired (see Section 7),
4.1.9 Special straightness, if required,
2. Referenced Documents
4.1.10 ASTM designation and date of issue,
2.1 ASTM Standards:
4.1.11 End use or special requirements, and
A 29/A 29M Specification for Steel Bars, Carbon and 4.1.12 Leaded steel, when required.
Alloy, Hot-Wrought and Cold-Finished, General Require-
NOTE 1—A typical ordering description is as follows: 10 000 lb, alloy
ments for
bars, round, 4.0 in. dia by 10 ft, Grade 1340H, J 40/56 5 ⁄16 in., heat
A 255 Test Method for End-Quench Test for Hardenability
analysis required, ASTM A 304, dated ________, worm gear.
of Steel
4.2 The purchaser shall specify the desired grade, including
E 112 Test Methods for Determining Average Grain Size
the suffix letter “H,” in accordance with Table 1 or Table 2.
E 527 Practice for Numbering Metals and Alloys (UNS)
4.3 Band limits are shown graphically and as tabulations in
Figs. 2-87, inclusive. For specifications purposes, the tabulated
3. Terminology
values of Rockwell C hardness are used. Values below 20
3.1 Definitions of Terms Specific to This Standard:
Rockwell C hardness (20 HRC) are not specified because such
3.1.1 hardenability—The relative ability of a steel to harden
values are below the normal range of the C scale. The graphs
under heat treatment becomes apparent in the degree to which
are shown for convenience in estimating the hardness values
the material hardens when quenched at different cooling rates.
obtainable at various locations on the end quench test bar and
It is measured quantitatively, usually by noting the extent or
for various locations in oil or water quenched rounds. The
depth of hardening of a standard size and shape test specimen
relationship between end-quench distance and bar diameter is
in a standardized quench. In the “end-quench” test the “depth
approximate and should be used only as a guide.
of hardening” is the distance along the specimen from the
4.4 Two points from the tabulated values are commonly
quenched end to a given hardness.
designated according to one of Methods A, B, C, D, or E,
which are defined in the following paragraphs. Those various
methods are illustrated graphically in Fig. 1.
This specification is under the jurisdiction of ASTM Committee A-1 on Steel,
4.4.1 Method A—The minimum and maximum hardness
Stainless Steel and Related Alloys,and is the direct responsibility of Subcommittee
values at any desired distance. This method is illustrated in Fig.
A01.15on Bars.
Current edition approved Nov. 10, 1996. Published September 1997. Originally 1 as points A-A and would be specified as 43 to 54 HRC at J3.
published as A 304 – 47 T. Last previous edition A 304 – 95.
Obviously the distance selected would be that distance on the
Annual Book of ASTM Standards, Vol 01.05.
end quench test bar which corresponds to the section used by
Annual Book of ASTM Standards, Vol 03.01.
the purchaser.
Annual Book of ASTM Standards, Vol 01.01.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
A 304
4.4.2 Method B—The minimum and maximum distances at purchaser and the manufacturer. Generally, hardenability bands
which any desired hardness value occurs. This method is will not be available for such compositions.
illustrated in Fig. 1 as points B- B and would be specified as 39 7.3 When requested by the manufacturer, and approved by
HRC at J4 minimum and J9 maximum. If the desired hardness the purchaser, other steels capable of meeting the purchaser’s
does not fall on an exact sixteenth position, the minimum specified hardenability may be furnished in place of the grade
distance selected should be the nearest sixteenth position specified by the purchaser.
toward the quenched end and the maximum should be the
8. Grain Size Requirements
nearest sixteenth position away from the quenched end.
4.4.3 Method C—Two maximum hardness values at two 8.1 The steel shall conform to the fine austenitic grain size
requirement of Specification A 29/A 29M.
desired distances, illustrated in Fig. 1 as points C-C.
4.4.4 Method D—Two minimum hardness values at two 8.2 Hardenability values specified herein are based on
fine-grain steels and are not applicable to coarse-grain material.
desired distances, illustrated in Fig. 1 as points D-D.
4.4.5 Method E—Any minimum hardness plus any maxi- In case coarse-grain steel is desired, the hardenability values
shall be negotiated between the purchaser and the manufac-
mum hardness. When hardenability is specified according to
one of the above Methods A to E, the balance of the turer.
hardenability band is not applicable.
9. End-Quench Hardenability Requirements
4.5 In cases when it is considered desirable, the maximum
9.1 The end-quench hardenability shall conform to the
and minimum limits at a distance of ⁄16in. from the quenched
requirements specified on the purchase order.
end can be specified in addition to the other two points as
previously described in 4.4.1 to 4.4.5, inclusive. 9.2 The hardenability values shall be specified in accor-
dance with the applicable values in Figs. 2-87 inclusive for the
4.6 In cases when it is necessary to specify more than two
points on the hardenability band (exclusive of the maximum grade specified. See Fig. 1 for method of specifying harden-
ability.
and minimum limits at a distance of ⁄16 in.), a tolerance of two
points Rockwell C (HRC) over any small portion of either 9.3 When agreed upon between the purchaser and manufac-
turer, special hardenability limits may be ordered and shall be
curve (except at a distance of ⁄16in.) is customary. This
tolerance is necessary because curves of individual heats vary reflected on the purchase order.
somewhat in shape from the standard band limits and thus
10. Test Specimens
deviate slightly at one or more positions in the full length of the
10.1 Number and Location—The number and location of
curves.
test specimens shall be in accordance with the manufacturer’s
5. Manufacture
standard practice and shall adequately represent the harden-
ability of each heat.
5.1 Melting Practice—The steel shall be made by one or
more of the following primary processes: open-hearth, basic- 10.2 Thermal Treatment—All forged or rolled hardenability
test specimens must be normalized prior to testing. Cast
oxygen, or electric-furnace. The primary melting may incor-
porate separate degassing or refining and may be followed by specimens need not be normalized.
secondary melting using electroslag remelting or vacuum arc
11. Test Methods
remelting. Where secondary melting is employed, the heat
11.1 Grain Size—Test Methods E 112.
shall be defined as all of the ingots remelted from a single
11.2 End-quench Hardenability—Test Method A 255.
primary heat.
5.2 Slow Cooling—Immediately after hot working, the bars
12. Certification and Reports of Testing
shall be allowed to cool when necessary to a temperature below
the critical range under suitable conditions, to prevent injury by 12.1 When the full H-band is specified for alloy steels, the
hardenability can be reported by listing hardness values at the
too rapid cooling.
following distances from the quenched end of the test speci-
6. General Requirements
men: 1 through 16 sixteenths, then 18, 20, 22, 24, 28, and 32
6.1 Material furnished under this specification shall con- sixteenths of an inch.
form to the applicable requirements of the current edition of 12.2 For carbon H-steels, distances from the quenched end
may be reported by listing sixteenths or half sixteenths (rather
Specification A 29/A 29M, unless otherwise provided for
herein. than full sixteenths only as with alloy steels). Units of
sixteenths rather than thirty-seconds are followed for all steels
7. Chemical Composition
to avoid misunderstanding. When the full H-band is specified
7.1 The heat analysis shall conform to the requirements as half sixteenths through 8 may be reported, as well as the
to chemical composition prescribed in Table 1 and Table 2 for distances listed in 12.1.
the grade specified by the purchaser.
13. Keywords
7.2 When a steel cannot be identified by a standard grade
number in accordance with Table 1 and Table 2, other 13.1 alloy steel bars; carbon steel bars; end quench harden-
compositions may be specified, as agreed upon between the ability; steel bars
A 304
A
TABLE 1 Chemical Requirements of Alloy H Steels
NOTE 1— Phosphorus and sulfur in open-hearth steel is 0.035 %, max, and 0.040 %, max respectively. Phosphorus and sulfur in electric-furnace steel
(designated by the prefix letter “E”) is 0.025 %, max.
NOTE 2—Small quantities of certain elements are present in alloy steels which are not specified or required. These elements are considered as incidental
and may be present to the following maximum amounts: copper, 0.35 %; nickel, 0.25 %; chromium, 0.20 %; molybdenum, 0.06 %.
NOTE 3—Chemical ranges and limits shown in this table are subject to the permissible variation for product analysis shown in Specification
A 29/A 29M.
NOTE 4—Standard “H” Steels can be produced with a lead range of 0.15–0.35 %. Such steels are identified by inserting the letter “L” between the
second and third numerals of the grade designation, for example, 41L40H. Lead is generally reported as a range of 0.15–0.35 %.
UNS Desig- Grade Designation Chemical Composition, %
A
nation
Carbon Manganese Silicon Nickel Chromium Molybdenum
H 13300 1330 H 0.27–0.33 1.45–2.05 0.15–0.35 . . .
H 13350 1335 H 0.32–0.38 1.45–2.05 0.15–0.35 . . .
H 13400 1340 H 0.37–0.44 1.45–2.05 0.15–0.35 . . .
H 13450 1345 H 0.42–0.49 1.45–2.05 0.15–0.35 . . .
H 40270 4027 H 0.24–0.30 0.60–1.00 0.15–0.35 . . 0.20–0.30
B
H 40280 4028 H 0.24–0.30 0.60–1.00 0.15–0.35 . . 0.20–0.30
H 40320 4032 H 0.29–0.35 0.60–1.00 0.15–0.35 . . 0.20–0.30
H 40370 4037 H 0.34–0.41 0.60–1.00 0.15–0.35 . . 0.20–0.30
H 40420 4042 H 0.39–0.46 0.60–1.00 0.15–0.35 . . 0.20–0.30
H 40470 4047 H 0.44–0.51 0.60–1.00 0.15–0.35 . . 0.20–0.30
H 41180 4118 H 0.17–0.23 0.60–1.00 0.15–0.35 . 0.30–0.70 0.08–0.15
H 41300 4130 H 0.27–0.33 0.30–0.70 0.15–0.35 . 0.75–1.20 0.15–0.25
H 41350 4135 H 0.32–0.38 0.60–1.00 0.15–0.35 . 0.75–1.20 0.15–0.25
H 41370 4137 H 0.34–0.41 0.60–1.00 0.15–0.35 . 0.75–1.20 0.15–0.25
H 41400 4140 H 0.37–0.44 0.65–1.10 0.15–0.35 . 0.75–1.20 0.15–0.25
H 41420 4142 H 0.39–0.46 0.65–1.10 0.15–0.35 . 0.75–1.20 0.15–0.25
H 41450 4145 H 0.42–0.49 0.65–1.10 0.15–0.35 . 0.75–1.20 0.15–0.25
H 41470 4147 H 0.44–0.51 0.65–1.10 0.15–0.35 . 0.75–1.20 0.15–0.25
H 41500 4150 H 0.47–0.54 0.65–1.10 0.15–0.35 . 0.75–1.20 0.15–0.25
H 41610 4161 H 0.55–0.65 0.65–1.10 0.15–0.35 . 0.65–0.95 0.25–0.35
H 43200 4320 H 0.17–0.23 0.40–0.70 0.15–0.35 1.55–2.00 0.35–0.65 0.20–0.30
H 43400 4340 H 0.37–0.44 0.55–0.90 0.15–0.35 1.55–2.00 0.65–0.95 0.20–0.30
C
H 43406 E4340 H 0.37–0.44 0.60–0.95 0.15–0.35 1.55–2.00 0.65–0.95 0.20–0.30
H 44190 4419 H 0.17–0.23 0.35–0.75 0.15–0.35 . . 0.45–0.60
H 46200 4620 H 0.17–0.23 0.35–0.75 0.15–0.35 1.55–2.00 . 0.20–0.30
H 46210 4621 H 0.17–0.23 0.60–1.00 0.15–0.35 1.55–2.00 . 0.20–0.30
H 46260 4626 0.23–0.29 0.40–0.70 0.15–0.35 0.65–1.05 . 0.15–0.25
H 47180 4718 H 0.15–0.21 0.60–0.95 0.15–0.35 0.85–1.25 0.30–0.60 0.30–0.40
H 47200 4720 H 0.17–0.23 0.45–0.75 0.15–0.35 0.85–1.25 0.30–0.60 0.15–0.25
H 48150 4815 H 0.12–0.18 0.30–0.70 0.15–0.35 3.20–3.80 . 0.20–0.30
H 48170 4817 H 0.14–0.20 0.30–0.70 0.15–0.35 3.20–3.80 . 0.20–0.30
H 48200 4820 H 0.17–0.23 0.40–0.80 0.15–0.35 3.20–3.80 . 0.20–0.30
D
H 50401 50B40 H 0.37–0.44 0.65–1.10 0.15–0.35 . 0.30–0.70 .
D
H 50441 50B44 H 0.42–0.49 0.65–1.10 0.15–0.35 . 0.30–0.70 .
H 50460 5046 H 0.43–0.50 0.65–1.10 0.15–0.35 . 0.13–0.43 .
D
H 50461 50B46 H 0.43–0.50 0.65–1.10 0.15–0.35 . 0.13–0.43 .
D
H 50501 50B50 H 0.47–0.54 0.65–1.10 0.15–0.35 . 0.30–0.70 .
D
H 50601 50B60 H 0.55–0.65 0.65–1.10 0.15–0.35 . 0.30–0.70 .
H 51200 5120 H 0.17–0.23 0.60–1.00 0.15–0.35 . 0.60–1.00 .
H 51300 5130 H 0.27–0.33 0.60–1.10 0.15–0.35 . 0.75–1.20 .
H 51320 5132 H 0.29–0.35 0.50–0.90 0.15–0.35 . 0.65–1.10 .
H 51350 5135 H 0.32–0.38 0.50–0.90 0.15–0.35 . 0.70–1.15 .
H 51400 5140 H 0.37–0.44 0.60–1.00 0.15–0.35 . 0.60–1.00 .
H 51450 5145 H 0.42–0.49 0.60–1.00 0.15–0.35 . 0.60–1.00 .
H 51470 5147 H 0.45–0.52 0.60–1.05 0.15–0.35 . 0.80–1.25 .
H 51500 5150 H 0.47–0.54 0.60–1.00 0.15–0.35 . 0.60–1.00 .
H 51550 5155 H 0.50–0.60 0.60–1.00 0.15–0.35 . 0.60–1.00 .
H 51600 5160 H 0.55–0.65 0.65–1.10 0.15–0.35 . 0.60–1.00 .
D
H 51601 51B60H 0.55–0.65 0.65–1.10 0.15–0.35 . 0.60–1.00 .
E
H 61180 6118 H 0.15–0.21 0.40–0.80 0.15–0.35 . 0.40–0.80 .
F
H61500 6150 H 0.47–0.54 0.60–1.00 0.15–0.35 . 0.75–1.20 .
D
H 81451 81B45 H 0.42–0.49 0.70–1.05 0.15–0.35 0.15–0.45 0.30–0.60 0.08–0.15
A 304
TABLE 1 Continued
UNS Desig- Grade Designation Chemical Composition, %
A
nation
Carbon Manganese Silicon Nickel Chromium Molybdenum
H 86170 8617 H 0.14–0.20 0.60–0.95 0.15–0.35 0.35–0.75 0.35–0.65 0.15–0.25
H 86200 8620 H 0.17–0.23 0.60–0.95 0.15–0.35 0.35–0.75 0.35–0.65 0.15–0.25
H 86220 8622 H
...