ASTM A681-94(1999)

Standard Specification for Tool Steels Alloy

SCOPE
1.1 This specification covers the chemical, mechanical, and physical requirements for available wrought alloy tool steel products.  
1.2 These products, which include hot or cold finished bar, plate, sheet, strip, rod, wire, or forgings, are normally fabricated into tools, dies, or fixtures. The selection of a material for a particular application will depend upon design, service conditions, and desired properties.  
1.3 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are provided for information only.

General Information

• Status: Historical
• Publication Date: 09-Sep-1999
• ICS: 77.140.10 - Heat-treatable steels
• Technical Committee: A01 - Steel, Stainless Steel and Related Alloys
• Drafting Committee: A01.29 - Tool Steels

Relations

• Replaced By: ASTM A681-94(2004) - Standard Specification for Tool Steels Alloy
• Effective Date: 10-Sep-1999
• Referred By: ASTM C704/C704M-15(2022)e1 - Standard Test Method for Abrasion Resistance of Refractory Materials at Room Temperature
• Effective Date: 10-Sep-1999
• Referred By: ASTM F1150-22 - Standard Specification for Commercial Food Waste Pulper and Waterpress Assembly
• Effective Date: 10-Sep-1999
• Referred By: ASTM F1899-14a(2019) - Standard Specification for Food Waste Pulper Without Waterpress Assembly
• Effective Date: 10-Sep-1999
• Referred By: ASTM B994/B994M-22 - Standard Specification for Nickel-Cobalt Alloy Coating
• Effective Date: 10-Sep-1999
• Referred By: ASTM F917-19 - Standard Specification for Commercial Food Waste Disposers
• Effective Date: 10-Sep-1999
• Referred By: ASTM F3215-22 - Standard Specification for Food Waste Dehydrators
• Effective Date: 10-Sep-1999

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: A 681 – 94 (Reapproved 1999)
Standard Specification for
Tool Steels Alloy
This standard is issued under the fixed designation A 681; 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 2.3 Federal Standards:
Fed. Std. No. 123 Marking and Shipment (Civil Agencies)
1.1 This specification covers the chemical, mechanical, and
Fed. Std. No. 183 Continuous Identification Marking of
physical requirements for available wrought alloy tool steel
Iron and Steel Products
products.
2.4 Other Standards:
1.2 These products, which include hot or cold finished bar,
SAE J1086 Recommended Practice for Numbering Metals
plate, sheet, strip, rod, wire, or forgings, are normally fabri-
and Alloys (UNS)
cated into tools, dies, or fixtures.The selection of a material for
a particular application will depend upon design, service
3. Classification
conditions, and desired properties.
3.1 Material in accordance with this specification is classi-
1.3 The values stated in inch-pound units are to be regarded
fied by chemical composition. Types correspond to respective
as the standard. The values given in parentheses are provided
AISI designations.
for information only.
3.1.1 Hot Work Tool Steels, Identification H:
2. Referenced Documents 3.1.1.1 Types H10 to H19 are characterized by a controlled
chromium content along with other alloying elements.The first
2.1 ASTM Standards:
four, containing molybdenum, offer excellent toughness and
A 370 Test Methods and Definitions for MechanicalTesting
high hardenability and are frequently used in cold work
of Steel Products
applications requiring toughness at relatively high hardness
A 561 Practice for Macroetch Testing of Tool Steel Bars
levels.
A 600 Specification for Tool Steel High Speed
3.1.1.2 Types H21 to H26 are characterized by a controlled
A 700 Practices for Packaging, Marking, and Loading
tungsten content along with other alloying elements. These
Methods for Steel Products for Domestic Shipment
steels offer greater resistance to the softening effect of elevated
E 3 Methods of Preparation of Metallographic Specimens
service temperatures but exhibit a lower degree of toughness.
E 30 Test Methods for Chemical Analysis of Steel, Cast
5 3.1.1.3 Types H41 to H43 are low-carbon modifications of
Iron, Open-Hearth Iron, and Wrought Iron
molybdenum high speed tool steels (Note 1) and have charac-
E 45 Test Methods for Determining the Inclusion Content
4 teristics similar to the tungsten types.
of Steel
E 59 PracticeforSamplingSteelandIronforDetermination
NOTE 1—High-speed tool steels are covered in Specification A 600.
of Chemical Composition
3.1.2 Cold Work Tool Steels, Identification A—Types A2 to
E 527 Practice for Numbering Metals and Alloys (UNS)
A10 cover a wide range of carbon and alloy contents but all
2.2 Military Standard:
have high hardenability and may be hardened in air. The low
MIL-STD-163 Steel Mill Products, Preparation for Ship-
carbon Types A8 and A9 have less wear resistance but offer
ment and Storage
greater toughness than others in this group. TypeA7, with high
carbon and vanadium, offers exceptional wear resistance but at
1 a very low level of toughness.
This specification is under the jurisdiction of ASTM Committee A-1 on Steel,
3.1.3 Cold Work Tool Steels, Identification D—Types D2 to
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
A01.29 on Tool Steels.
D7 are characterized by high carbon and high chromium
Current edition approved June 15, 1994. Published August 1994. Originally
contents and exhibit high resistance to abrasion. The types
published as A 681 – 73. Last previous edition A 681 – 92.
containing molybdenum may be hardened in air and offer a
Annual Book of ASTM Standards, Vol 01.03.
Annual Book of ASTM Standards, Vol 01.05. high degree of dimensional stability in heat treatment.
Annual Book of ASTM Standards, Vol 03.01.
Annual Book of ASTM Standards, Vol 03.05.
Annual Book of ASTM Standards, Vol 01.01.
7 8
Available from the Standardization Documents, Order Desk, Bldg. 4, Section Available from the Society ofAutomotive Engineers, 400 Commonwelth drive,
D 700 Robbins Ave. Philadelphia, PA 19111-5094 Attn: NPODS. Warrendale, PA 15096.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A 681 – 94 (1999)
3.1.4 Cold Work Tool Steels, Identification O—Types O1 to 7. Hardness Requirements
O7 are low-alloy types that must be hardened by quenching in
7.1 Annealed hardness values shall be obtained in accor-
oil. Sizes over about 2 in. (50 mm) in cross section usually
dance with the latest issue of Test Methods and Definitions
exhibit lower interior hardness.
A 370, and shall not exceed the Brinell hardness values (or
3.1.5 Shock-Resisting Steels, Identification S—Types S1 to
equivalent Rockwell hardness values) specified in Table 2.
S7 vary in alloy content but are intended for shock-resisting
7.2 Specimens for determination of minimum response to
applications.
hardening shall be ⁄4 -in. (6.4-mm) thick disks cut so as to
3.1.6 Special-Purpose Tool Steels, Identification L—Types
represent either the full cross-sectional area or that midway
L2 to L6 are low-alloy steels with a wide range of carbon
between the center and outer surface of the material. If the
content. The low-carbon types are generally used for structural
material form or size does not lend itself to accurate hardness
applications requiring good levels of toughness, while the
determination on ⁄4 -in. thick cross-sectional disks, then
high-carbon types may be used for short-run tools.
longitudinal specimens may be used for hardness testing.
3.1.7 Special-Purpose Tool Steels, Identification F—Types
Examples are round bars less than ⁄2 in. (12.7 mm) in diameter
F1 to F2 are high-carbon steels with varying tungsten content
or sheet. In this case, the specimen shall be a minimum of 3 in.
used primarily for relatively short-run fine edge cutting tools.
(76 mm) in length and parallel flats shall be ground on the
3.1.8 Mold Steels, Identification P:
original mill surfaces. The specimens shall be heat treated as
3.1.8.1 Types P2 to P6 are very low-carbon steels and must
prescribed in Table 3.
be carburized after machining or hubbing.
3.1.8.2 Types P20 and P21 are usually supplied in the
7.2.1 The hardness of the specimen after the specified heat
prehardened condition and can be placed in service directly
treatment shall meet the minimum hardness value for the
after machining.
particular type of steel shown in Table 3. Rockwell C tests
should be used where possible but light load tests may be
4. Ordering Information
necessaryonthinspecimens.Thesetestsshouldbespecifiedby
4.1 Orders for material under this specification shall include
agreement between the seller and the purchaser. The hardness
the following information, as required to describe adequately
value shall be obtained in accordance with the latest issue of
the desired material:
Test Methods and Definitions A 370, and shall be the average
4.1.1 Class of material (hot work tool steel, etc.),
of at least five readings taken in an area midway between the
4.1.2 Type (H11, D2, etc.),
center and surface of the largest dimension of the cross-
4.1.3 Shape (sheet, strip, plate, flat bar, round bar, square
sectional specimen or along the parallel surfaces of the
bar, hexagon bar, octagon, special shapes),
longitudinal specimen.
4.1.4 Dimensions (thickness, width, diameter, length),
4.1.5 Finish (hot rolled, forged, blasted or pickled, cold
8. Macrostructure
drawn, machined, ground, precision ground and polished),
8.1 Specimens for the determination of the macrostructure
4.1.6 Condition (annealed, hardened and tempered, etc.),
shall represent the entire cross-sectional area in the annealed
4.1.7 ASTM designation and year of issue, and
conditionandbepreparedinaccordancewiththelatestissueof
4.1.8 Special requirements.
Practice A 561. Material supplied to this specification shall be
5. Materials and Manufacture
capable of exhibiting a structure free of excessive porosity,
5.1 Unless otherwise specified, material covered by this segregation, slag, dirt or other nonmetallic inclusions, pipe,
checks, cracks, and other injurious defects.
specification shall be made by an electric melting process. It
shall be made from ingots that have been reduced in cross
8.2 Macroetch severity levels for center porosity and ingot
section in such a manner and to such a degree as to ensure
pattern,illustratedphotographicallyinPracticeA 561,shallnot
proper refinement of the ingot structure.
exceed the ratings specification in Table 4 for the appropriate
materialsizeandcomposition.Morestringentrequirementsare
6. Chemical Composition
available by agreement between seller and purchaser.
6.1 An analysis of each heat of steel shall be made by the
manufacturer to determine the percentage of the elements
9. Decarburization
specified, and these values shall conform to the requirements
9.1 Specimens for the determination of decarburization
for chemical composition specified in Table 1. If requested or
shall represent a cross section of the material and be prepared
required, the chemical composition shall be reported to the
in accordance with the latest issue of Methods E 3. Material
purchaser or his representative.
supplied to this specification shall be capable, when examined
6.2 Analysis may be made by the purchaser from finished
at 20 times or greater magnification, of not exceeding the
bars and forgings by machining off the entire cross section and
values given inTables 5-8 for the appropriate size and shape of
drilling parallel to the axis of the bar or forging at any point
material. Lower limits of decarburization may be specified by
midway between the center and surface in accordance with the
agreement between the seller and purchaser.
latest issue of Practice E 59. The chemical analysis of the
drilling chips shall be made in accordance with the latest issue 9.2 Material ordered as ground and polished or ground
of Test Methods E 30. The chemical composition thus deter- finished or machine finished shall be free of scale and
mined shall not vary from the limits specified in Table 1. decarburization.
A 681 – 94 (1999)
A
TABLE 1 Chemical Requirements, %
C
UNS Carbon Manganese Phos- Silicon Chromium Vanadium Tungsten Molybdenum
D
Sulfur,
Desig- Type phorus,
max
B
min max min max min max min max min max min max min max
nation max
T20810 H10 0.35 0.45 0.20 0.70 0.030 0.030 0.80 1.25 3.00 3.75 0.25 0.75 . . . . . . 2.00 3.00
T20811 H11 0.33 0.43 0.20 0.60 0.030 0.030 0.80 1.25 4.75 5.50 0.30 0.60 . . . . . . 1.10 1.60
T20812 H12 0.30 0.40 0.20 0.60 0.030 0.030 0.80 1.25 4.75 5.50 0.20 0.50 1.00 1.70 1.25 1.75
T20813 H13 0.32 0.45 0.20 0.60 0.030 0.030 0.80 1.25 4.75 5.50 0.80 1.20 . . . . . . 1.10 1.75
T20814 H14 0.35 0.45 0.20 0.60 0.030 0.030 0.80 1.25 4.75 5.50 . . . . . . 4.00 5.25 . . . . . .
T20819 H19 0.32 0.45 0.20 0.50 0.030 0.030 0.15 0.50 4.00 4.75 1.75 2.20 3.75 4.50 0.30 0.55 Co 4.00–4.50
T20821 H21 0.26 0.36 0.15 0.40 0.030 0.030 0.15 0.50 3.00 3.75 0.30 0.60 8.50 10.00 . . . . . .
T20822 H22 0.30 0.40 0.15 0.40 0.030 0.030 0.15 0.40 1.75 3.75 0.25 0.50 10.00 11.75 . . . . . .
T20823 H23 0.25 0.35 0.15 0.40 0.030 0.030 0.15 0.60 11.00 12.75 0.75 1.25 11.00 12.75 . . . . . .
T20824 H24 0.42 0.53 0.15 0.40 0.030 0.030 0.15 0.40 2.50 3.50 0.40 0.60 14.00 16.00 . . . . . .
T20825 H25 0.22 0.32 0.15 0.40 0.030 0.030 0.15 0.40 3.75 4.50 0.40 0.60 14.00 16.00 . . . . . .
E
T20826 H26 0.45 0.55 0.15 0.40 0.030 0.030 0.15 0.40 3.75 4.50 0.75 1.25 17.25 19.00 . . . . . .
E
T20841 H41 0.60 0.75 0.15 0.40 0.030 0.030 0.20 0.45 3.50 4.00 1.00 1.30 1.40 2.10 8.20 9.20
E
T20842 H42 0.55 0.70 0.15 0.40 0.030 0.030 0.20 0.45 3.75 4.50 1.75 2.20 5.50 6.75 4.50 5.50
E
T20843 H43 0.50 0.65 0.15 0.40 0.030 0.030 0.20 0.45 3.75 4.50 1.80 2.20 . . . . . . 7.75 8.50
T30102 A2 0.95 1.05 0.40 1.00 0.030 0.030 0.10 0.50 4.75 5.50 0.15 0.50 . . . . . . 0.90 1.40
T30103 A3 1.20 1.30 0.40 0.60 0.030 0.030 0.10 0.70 4.75 5.50 0.80 1.40 . . . . . . 0.90 1.40
T30104 A4 0.95 1.05 1.80 2.20 0.030 0.030 0.10 0.70 0.90 2.20 . . . . . . . . . . . . 0.90 1.40
T30105 A5 0.95 1.05 2.80 3.20 0.030 0.030 0.10 0.70 0.90 1.40 . . . . . . . . . . . . 0.90 1.40
T30106 A6 0.65 0.75 1.80 2.50 0.030 0.030 0.10 0.70 0.90 1.40 . . . . . . . . . . . . 0.90 1.40
T30107 A7 2.00 2.85 0.20 0.80 0.030 0.030 0.10 0.70 5.00 5.75 3.90 5.15 0.50 1.50 0.90 1.40
T30108 A8 0.50 0.60 0.20 0.50 0.030 0.030 0.75 1.10 4.75 5.50 . . . . . . 1.00 1.50 1.15 1.65
T30109 A9 0.45 0.55 0.20 0.50 0.030 0.030 0.95 1.15 4.75 5.50 0.80 1.40 . . . . . . 1.30 1.80 Ni 1.25–1.75
T30110 A10 1.25 1.50 1.60 2.10 0.030 0.030 1.00 1.50 . . . . . . . . . . . . . . . . . . 1.25 1.75 Ni 1.55–2.05
T30402 D2 1.40 1.60 0.10 0.60 0.030 0.030 0.10 0.60 11.00 13.00 0.50 1.10 . . . . . . 0.70 1.20 . . .
T30403 D3 2.00 2.35 0.10 0.60 0.030 0.030 0.10 0.60 11.00 13.50 . . . 1.00 . . . 1.00 . . . . . .
T30404 D4 2.05 2.40 0.10 0.60 0.030 0.030 0.10 0.60 11.00 13.00 0.15 1.00 . . . . . . 0.70 1.20
T30405 D5 1.40 1.60 0.10 0.60 0.030 0.030 0.10 0.60 11.00 13.00 . . . 1.00 . . . . . . 0.70 1.20 Co 2.50–3.50
T30407 D7 2.15 2.50 0.10 0.60 0.030 0.030 0.10 0.60 11.50 13.50 3.80 4.40 . . . . . . 0.70 1.20
T31501 O1 0.85 1.00 1.00 1.40 0.030 0.030 0.10 0.50 0.40 0.70 . . . 0.30 0.40 0.60 . . . . . .
T31502 O2 0.85 0.95 1.40 1.80 0.030 0.030 . . . 0.50 . . . 0.50 . . . 0.30 . . . . . . . . . 0.30
T31506 O6 1.25 1.55 0.30 1.10 0.030 0.030 0.55 1.50 . . . 0.30 . . . . . . . . . . . . 0.20 0.30
T31507 O7 1.10 1.30 0.20 1.00 0.030 0.030 0.10 0.60 0.35 0.85 0.15 0.40 1.00 2.00 . . . 0.30
T41901 S1 0.40 0.55 0.10 0.40 0.030 0.030 0.15 1.20 1.00 1.80 0.15 0.30 1.50 3.00 . . . 0.50
T41902 S2 0.40 0.55 0.30 0.50 0.030 0.030 0.90 1.20 . . . . . . . . . 0.50 . . . . . . 0.30 0.60
T41904 S4 0.50 0.65 0.60 0.95 0.030 0.030 1.75 2.25 0.10 0.50 0.15 0.35 . . . . . . . . . . . . . . . . . .
T41905 S5 0.50 0.65 0.60 1.00 0.030 0.030 1.75 2.25 0.10 0.50 0.15 0.35 . . . . . . 0.20 1.35 . . . . . .
T41906 S6 0.40 0.50 1.20 1.50 0.030 0.030 2.00 2.50 1.20 1.50 0.20 0.40 . . . . . . 0.30 0.50 . . . . . .
T41907 S7 0.45 0.55 0.20 0.90 0.030 0.030 0.20 1.00 3.00 3.50 . . . 0.35 . . . . . . 1.30 1.80 . . . . . .
T61202 L2 0.45 1.00 0.10 0.90 0.030 0.030 0.10 0.50 0.70 1.20 0.10 0.30 . . . . . . . . . 0.25 . . . .
...