ASTM A686-92(2016)

Standard Specification for Tool Steel, Carbon

ABSTRACT
This specification covers chemical, mechanical, and physical requirements for available wrought carbon tool steel products. These products, which include hot- or cold-finished bar, plate, sheet, 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. An analysis of each heat of steel shall be made by the manufacturer to determine the percentage of the elements specified and these values shall conform to the chemical composition specified by the reference material. The hardness of the specimen after the specified heat treatment shall meet the minimum hardness value for the particular type of steel prescribed by the reference material. Rockwell C tests should be used where possible but light load tests may be necessary on thin specimens. The macrostructure of a specimen representing the entire cross-sectional area in the annealed condition shall be prepared in accordance with the reference material. It shall exhibit a structure free of excessive porosity, segregation, slag, dirt or other nonmetallic inclusions, pipes, checks, cracks, and other injurious defects.
SCOPE
1.1 This specification covers the chemical, mechanical, and physical requirements for available wrought carbon tool steel products.  
1.2 These products, which include hot- or cold-finished bar, plate, sheet, 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 standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

General Information

• Status: Historical
• Publication Date: 29-Feb-2016
• ICS: 77.140.10 - Heat-treatable steels
• Technical Committee: A01 - Steel, Stainless Steel and Related Alloys
• Drafting Committee: A01.29 - Tool Steels

Relations

• Replaces: ASTM A686-92(2010) - Standard Specification for Tool Steel, Carbon
• Effective Date: 01-Mar-2016
• Replaced By: ASTM A686-92(2024) - Standard Specification for Tool Steel, Carbon
• Effective Date: 01-Mar-2024
• Refers: ASTM A388/A388M-23 - Standard Practice for Ultrasonic Examination of Steel Forgings
• Effective Date: 01-Nov-2023
• Refers: ASTM E45-18a(2023) - Standard Test Methods for Determining the Inclusion Content of Steel
• Effective Date: 01-Nov-2023
• Refers: ASTM A561-08(2020) - Standard Practice for Macroetch Testing of Tool Steel Bars
• Effective Date: 01-Mar-2020
• Refers: ASTM A700-14(2019) - Standard Guide for Packaging, Marking, and Loading Methods for Steel Products for Shipment
• Effective Date: 01-Nov-2019
• Refers: ASTM A370-19 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 01-Jul-2019
• Refers: ASTM A370-17a - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 15-Nov-2017
• Refers: ASTM A370-17 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 01-Jan-2017
• Refers: ASTM A370-15 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 01-Nov-2015
• Refers: ASTM A700-14 - Standard Guide for Packaging, Marking, and Loading Methods for Steel Products for Shipment
• Effective Date: 01-Nov-2014
• Refers: ASTM A370-14 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 15-May-2014
• Refers: ASTM A561-08(2014) - Standard Practice for Macroetch Testing of Tool Steel Bars
• Effective Date: 01-Mar-2014
• Refers: ASTM A370-13 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 15-Nov-2013
• Refers: ASTM A370-12a - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 15-Oct-2012

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:A686 −92 (Reapproved 2016)
Standard Specification for
Tool Steel, Carbon
This standard is issued under the fixed designation A686; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 2.2 Military Standard:
MIL-STD-163Steel Mill Products, Preparation for Ship-
1.1 This specification covers the chemical, mechanical, and
ment and Storage
physical requirements for available wrought carbon tool steel
2.3 Federal Standards:
products.
Fed. Std. No. 123Marking for Shipment (Civil Agencies)
1.2 These products, which include hot- or cold-finished bar,
Fed.Std.No.183ContinuousIdentificationMarkingofIron
plate,sheet,rod,wire,orforgings,arenormallyfabricatedinto
and Steel Products
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 standard. The values given in parentheses are mathematical
AISI designations.
conversions to SI units that are provided for information only
3.1.1 Carbon Tool Steels, Identification W—TypesW1,W2,
and are not considered standard.
and W5 are often referred to as water hardening tool steels
since they require rapid quenching rates to attain the necessary
2. Referenced Documents
hardness. Except in very small sizes they will harden with a
2.1 ASTM Standards:
hard case and a soft core.
A370Test Methods and Definitions for Mechanical Testing 3.1.1.1 Type W1 is an unalloyed carbon steel available in
of Steel Products
several carbon ranges.
A388/A388MPractice for Ultrasonic Examination of Steel 3.1.1.2 Type W2 is characterized by a nominal vanadium
Forgings
content of 0.25% and is also available in several carbon
A561Practice for Macroetch Testing of Tool Steel Bars ranges.
A700Guide for Packaging, Marking, and Loading Methods
3.1.1.3 Type W5 is characterized by a nominal chromium
for Steel Products for Shipment content of 0.50%.
E3Guide for Preparation of Metallographic Specimens
3.1.1.4 A suffix following the type designation is added to
E30TestMethodsforChemicalAnalysisofSteel,CastIron, denote the minimum carbon content of the carbon range to be
Open-Hearth Iron, and Wrought Iron (Withdrawn 1995)
specified.
E45Test Methods for Determining the Inclusion Content of 3.1.2 Types W1 and W2 are further classified by quality
Steel
levels, namely, Grade A and Grade C.
E59Practice for Sampling Steel and Iron for Determination 3.1.2.1 GradeAissometimesreferredtoas Extraor Special.
of Chemical Composition (Withdrawn 1996)
It is controlled for hardenability; the chemical composition is
held to closest limits; and it is subject to rigid tests to ensure
uniformity. Grade A is available with three degrees of
This specification is under the jurisdiction ofASTM Committee A01 on Steel, hardenability, namely, shallow hardening, regular hardening,
Stainless Steel and RelatedAlloys and is the direct responsibility of Subcommittee
and deep hardening.
A01.29 on Tool Steels.
3.1.2.2 Grade C is sometimes referred to as Regular or
Current edition approved March 1, 2016. Published June 2016. Originally
Standard. It is intended for applications that do not require
approved in 1973. Last previous edition approved in 2010 as A686–92 (2010).
DOI: 10.1520/A0686-92R16.
controlledhardenabilityandwheresomelatitudeinuniformity
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
is permissible.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
3 4
The last approved version of this historical standard is referenced on Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
www.astm.org. Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A686−92 (2016)
4. Ordering Information midway between the center and surface in accordance with the
latest issue of Practice E59. The chemical analysis of the
4.1 Ordersformaterialunderthisspecificationshallinclude
drilling chips shall be made in accordance with the latest issue
the following information, as required to describe adequately
of Test Methods E30. The chemical composition thus deter-
the desired material:
mined shall not vary from the limits specified in Table 1.
4.1.1 Class of material (carbon tool steel),
4.1.2 Type (W1, W2, W5),
7. Hardness Properties
4.1.3 Suffix denoting carbon range (where applicable, such
as W1–9, W2–10, etc.),
7.1 Annealed hardness values shall be obtained in accor-
4.1.4 Grade and hardenability (where applicable, for
dance with the latest issue of Test Methods and Definitions
example, Grade A deep hardening, and so forth),
A370, and shall not exceed the Brinell hardness values (or
4.1.5 Shape (sheet, plate, flat bar, round bar, square bar,
equivalent Rockwell hardness values) specified in Table 2.
hexagon bar, octagon, special shapes),
7.2 Specimens for determination of minimum response to
4.1.6 Dimensions (thickness, width, diameter, length),
hardening shall be ¼-in. (6.4-mm) thick disks cut so as to
4.1.7 Finish (hot rolled, forged, blasted or pickled, cold
represent either the full cross-sectional area or that midway
drawn, machined, ground, precision ground and polished),
between the center and outer surface of the material. If the
4.1.8 Condition (annealed, unannealed, hardened and
material form or size does not lend itself to accurate hardness
tempered, and so forth),
determination on ¼-in. (6.4-mm) thick cross-sectional disks,
4.1.9 ASTM specification number and date of issue, and
then longitudinal specimens may be used for hardness testing.
4.1.10 Special requirements.
Examplesareroundbarslessthan ⁄2in.(12.7mm)indiameter
orsheet.Inthiscase,thespecimenshallbeaminimumof3in.
5. Materials and Manufacture
(76.2 mm) in length and parallel flats shall be ground on the
5.1 Unless otherwise specified, material covered by this
original mill surfaces. The specimens shall be heat treated as
specification shall be made by an electric melting process. It
prescribed in Table 3.
shall be made from ingots that have been reduced in cross
7.2.1 The hardness of the specimen after the specified heat
section in such a manner and to such a degree as to ensure
treatment shall meet the minimum hardness value for the
proper refinement of the ingot structure.
particular type of steel shown in Table 3. Rockwell C tests
should be used where possible but light load tests may be
6. Chemical Composition
necessaryonthinspecimens.Thesetestsshouldbespecifiedby
6.1 An analysis of each heat of steel shall be made by the
agreement between seller and purchaser. The hardness value
manufacturer to determine the percentage of the elements
shall be obtained in accordance with the latest issue of Test
specified and these values shall conform to the chemical
Methods and Definitions A370, and shall be the average of at
composition specified in Table 1. If requested or required, the
least five readings taken in an area midway between the center
chemical composition shall be reported to the purchaser or his
and surface of the largest dimension of the cross-sectional
representative.
specimen or along the parallel surfaces of the longitudinal
6.2 Analysis may be made by the purchaser from finished specimen. The surface to be tested shall be ground sufficiently
bars and forgings by machining off the entire cross section and to remove any surface condition, scale, carburization, or
drilling parallel to the axis of the bar or forging at any point decarburization which might affect readings.
A
TABLE 1 Chemical Composition,%
Man- Phos-
UNS Tung- Molyb-
Carbon Silicon Chromium Vanadium
Sulfur, Copper, Nickel,
ganese phorus,
Desig- Type Grade sten, denum,
max max max
max
nation max max
min max min max min max min max min max
BB
T72301 W1 A 0.10 0.40 0.10 0.40 0.030 0.030 . . . 0.15 . . . 0.10 0.15 0.10 0.20 0.20
BB
T72301 W1 C 0.10 0.40 0.10 0.40 0.030 0.030 . . . 0.30 . . . 0.10 0.15 0.10 0.20 0.20
CC
T72302 W2 A 0.10 0.40 0.10 0.40 0.030 0.030 . . . 0.15 0.15 0.35 0.15 0.10 0.20 0.20
CC
T72302 W2 C 0.10 0.40 0.10 0.40 0.030 0.030 . . . 0.30 0.15 0.35 0.15 0.10 0.20 0.20
T72305 W5 . 1.05 1.15 0.10 0.40 0.10 0.40 0.030 0.030 0.40 0.60 . . . 0.10 0.15 0.10 0.20 0.20
A
Chemistry limits include product analysis tolerances.
B
The carbon ranges for W1 and their respective suffix identification, sometimes referred to as tempers, are as follows:
Suffix Carbon Range, % Suffix Carbon Range, %
8 0.80–0.90 10 1.00–1.10
1 1
8 ⁄2 0.85–0.95 10 ⁄2 1.05–1.15
9 0.90–1.00 11 1.10–1.20
1 1
9 ⁄2 0.95–1.05 11 ⁄2 1.15–1.25
C
The carbon ranges for W2 and their respective suffix identification are as follows:
Suffix Carbon Range, %
8 ⁄2 0.85–0.95
9 0.90–1.00
9 ⁄2 0.95–1.10
13 1.30–1.50
A686−92 (2016)
TABLE 2 Maximum Brinell Hardness in Annealed or Cold Drawn
given in Tables 5-9 for the appropriate size and shape of
Condition
material. Lower limits of decarburization may be specified by
Type Annealed BHN Cold Drawn BHN
agreement between the seller and purchaser.
W1 202 241
W2 202 241
9.2 Material ordered as ground and polished or ground
W5 202 241
finished or machine finished shall be free of scale and
Drill Rod (W1, W2, or W5)
decarburization.
Ordered Diameter, in. (mm) Brinell Rockwell
To ⁄8 (3.2) HB 341 HRC 37
10. Permissible Variations for Dimensions
1 1
Over ⁄8 to ⁄4 (3.2 to 6.4), incl HB 275 HRC 28
1 1
Over ⁄4 to ⁄2 (6.4 to 12.7), incl HB 241 HRC 23
10.1 Permissible variations for dimensions shall not exceed
Over ⁄2 (12.7) HB 207 HRB 96
the applicable limits stated in Table 6, and Tables 10-22 and
Note 1.
NOTE 1—Unmachined tool steel forgings are furnished to size and
7.2.2 HardnesspenetrationandfracturegrainsizeforGrade
surface allowances for machining and tolerances over allowances. Expe-
A shall be determined on test pieces of ⁄4 in. (19.1 mm)
rienceindicatesthattheallowancesandtolerancesinthetabulationbelow
diameter and 3 in. (76.2 mm) length. Two pieces for each test
are satisfactory for many applications. When width and thickness differ,
shall be given a preliminary treatment by heating uniformly to each dimension carries its individual allowance and tolerance in accor-
dance with the tabulation: also, the ID and OD take their respective
1600 6 10°F (871 6 5°C) and holding at temperature for
allowances and tolerances. When forgings are ordered, the purchaser
40min, then quenching in oil. One piece shall be reheated to
should state whether the sizes are the forged or the finished sizes. The
1450 610°F (788 6 5°C) and the other to 1550 6 10°F
minimum sizes ordered for forgings should be the finished sizes plus
(843 6 5°C). Each piece shall be held in the furnace at the
allowances for machining; and the ordered forged sizes are subject to
applicable tolerances
respective temperature for 30 min and then quenched in brine
(5 to 10% sodium chloride solution). The pieces shall be
10.2 Out-of-round tolerances for round bars shall be one
nicked with an abrasive wheel in the center of the length and
half the permissible dimensional variations stated in Table 6,
fractured. The fracture face of one portion of each broken test
Table 10, Table 12, Table 14, Table 15, and Table 17.
pieceshallbegroundsmoothandetchedin1+1muriaticacid
11. Workmanship, Finish, and Appearance
at165°F(74°C)formeasurementofthedepthofpenetrationto
be expressed in 64ths of an inch. The fracture grain size shall
11.1 Allcarbontoolsteelsshallbefreeofheavyscale,deep
be determined on the remaining portion of each broken test
pitting, laps, porosity, injurious segregations, excessive non-
piece by comparison of the fracture surface of the hardened
metallicinclusions,seams,cracks,checks,slivers,scalemarks,
case with the Shepherd Fracture Grain Size Standards. These
dents, soft and hard spots, pipes, or any defects that would
standards consist of ten pieces of steel with fracture faces
detrimentallyaffectthesuitabilityofthematerialafterremoval
representing graduated grain sizes from the coarsest (No. 1) to
of the recommended stock allowance.
the finest (No. 10). The fracture grain size is estimated to the
12. Sampling
nearest quarter number. The hardness penetration and fracture
grain size for Grade A shall meet the requirements shown in
12.1 Each particular shipment of a heat of steel by type,
Table 3.
size, and shape shall be considered a lot and must conform to
the provisions of this specification.
8. Macrostructure
13. Inspection
8.1 The macrostructure of a specimen representing the
entire cross-sectional area in the annealed condition shall be
13.1 When specified in the purchase order, the inspector
prepared in accordance with the latest issue of Practice A561.
representing the purchaser shall have access to the material
It shall exhibit a structure free of excessive porosity,
subjecttoinspectionforthepurposeofwitnessingtheselection
segregation, slag, dirt or other nonmetallic inclusions, pipes,
of samples, preparation of test pieces, and performance of the
checks, cracks, and other injurious defects.
tests. For such tests, the inspector shall have the right to
indicate the pieces from which samples will be selected.
8.2 Macroetch severity levels for center porosity and ingot
Otherwise, the seller shall report to the purchaser, or his
pattern,illustratedphotographicallyinPracticeA561,shallnot
representative, the results of the chemical analysis and the
exceed the ratings specification in Table 4 for the appropriate
physical and mechanical property tests made in accordance
materialsizeandcomposition.Morestringentrequirementsare
with this specification.
available by agreement between seller and purchaser.
14. Rejection and Rehearing
9. Decarburization
14.1 Unless otherwise specified, any rejections based on
9.1 Decarburization shall be determined on a specimen
tests made in accordance with this specification shall be
representing a cross section of the material and prepared in
reportedtothesellerwithin30daysfromthedateofreceiptof
acc
...

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: A686 − 92 (Reapproved 2016)
Standard Specification for
Tool Steel, Carbon
This standard is issued under the fixed designation A686; 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 (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 2.2 Military Standard:
MIL-STD-163 Steel Mill Products, Preparation for Ship-
1.1 This specification covers the chemical, mechanical, and
ment and Storage
physical requirements for available wrought carbon tool steel
2.3 Federal Standards:
products.
Fed. Std. No. 123 Marking for Shipment (Civil Agencies)
1.2 These products, which include hot- or cold-finished bar,
Fed. Std. No. 183 Continuous Identification Marking of Iron
plate, sheet, rod, wire, or forgings, are normally fabricated into
and Steel Products
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 standard. The values given in parentheses are mathematical
AISI designations.
conversions to SI units that are provided for information only
3.1.1 Carbon Tool Steels, Identification W—Types W1, W2,
and are not considered standard.
and W5 are often referred to as water hardening tool steels
since they require rapid quenching rates to attain the necessary
2. Referenced Documents
hardness. Except in very small sizes they will harden with a
2.1 ASTM Standards: hard case and a soft core.
A370 Test Methods and Definitions for Mechanical Testing
3.1.1.1 Type W1 is an unalloyed carbon steel available in
of Steel Products several carbon ranges.
A388/A388M Practice for Ultrasonic Examination of Steel
3.1.1.2 Type W2 is characterized by a nominal vanadium
Forgings content of 0.25 % and is also available in several carbon
A561 Practice for Macroetch Testing of Tool Steel Bars
ranges.
A700 Guide for Packaging, Marking, and Loading Methods 3.1.1.3 Type W5 is characterized by a nominal chromium
for Steel Products for Shipment
content of 0.50 %.
E3 Guide for Preparation of Metallographic Specimens 3.1.1.4 A suffix following the type designation is added to
E30 Test Methods for Chemical Analysis of Steel, Cast Iron,
denote the minimum carbon content of the carbon range to be
Open-Hearth Iron, and Wrought Iron (Withdrawn 1995) specified.
E45 Test Methods for Determining the Inclusion Content of
3.1.2 Types W1 and W2 are further classified by quality
Steel levels, namely, Grade A and Grade C.
E59 Practice for Sampling Steel and Iron for Determination
3.1.2.1 Grade A is sometimes referred to as Extra or Special.
of Chemical Composition (Withdrawn 1996) It is controlled for hardenability; the chemical composition is
held to closest limits; and it is subject to rigid tests to ensure
uniformity. Grade A is available with three degrees of
hardenability, namely, shallow hardening, regular hardening,
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
and deep hardening.
A01.29 on Tool Steels.
3.1.2.2 Grade C is sometimes referred to as Regular or
Current edition approved March 1, 2016. Published June 2016. Originally
Standard. It is intended for applications that do not require
approved in 1973. Last previous edition approved in 2010 as A686 – 92 (2010).
DOI: 10.1520/A0686-92R16. controlled hardenability and where some latitude in uniformity
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
is permissible.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
3 4
The last approved version of this historical standard is referenced on Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
www.astm.org. Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A686 − 92 (2016)
4. Ordering Information midway between the center and surface in accordance with the
latest issue of Practice E59. The chemical analysis of the
4.1 Orders for material under this specification shall include
drilling chips shall be made in accordance with the latest issue
the following information, as required to describe adequately
of Test Methods E30. The chemical composition thus deter-
the desired material:
mined shall not vary from the limits specified in Table 1.
4.1.1 Class of material (carbon tool steel),
4.1.2 Type (W1, W2, W5),
7. Hardness Properties
4.1.3 Suffix denoting carbon range (where applicable, such
as W1–9, W2–10, etc.),
7.1 Annealed hardness values shall be obtained in accor-
4.1.4 Grade and hardenability (where applicable, for
dance with the latest issue of Test Methods and Definitions
example, Grade A deep hardening, and so forth),
A370, and shall not exceed the Brinell hardness values (or
4.1.5 Shape (sheet, plate, flat bar, round bar, square bar,
equivalent Rockwell hardness values) specified in Table 2.
hexagon bar, octagon, special shapes),
7.2 Specimens for determination of minimum response to
4.1.6 Dimensions (thickness, width, diameter, length),
hardening shall be ¼-in. (6.4-mm) thick disks cut so as to
4.1.7 Finish (hot rolled, forged, blasted or pickled, cold
represent either the full cross-sectional area or that midway
drawn, machined, ground, precision ground and polished),
between the center and outer surface of the material. If the
4.1.8 Condition (annealed, unannealed, hardened and
material form or size does not lend itself to accurate hardness
tempered, and so forth),
determination on ¼-in. (6.4-mm) thick cross-sectional disks,
4.1.9 ASTM specification number and date of issue, and
then longitudinal specimens may be used for hardness testing.
4.1.10 Special requirements.
Examples are round bars less than ⁄2 in. (12.7 mm) in diameter
or sheet. In this case, the specimen shall be a minimum of 3 in.
5. Materials and Manufacture
(76.2 mm) in length and parallel flats shall be ground on the
5.1 Unless otherwise specified, material covered by this
original mill surfaces. The specimens shall be heat treated as
specification shall be made by an electric melting process. It
prescribed in Table 3.
shall be made from ingots that have been reduced in cross
7.2.1 The hardness of the specimen after the specified heat
section in such a manner and to such a degree as to ensure
treatment shall meet the minimum hardness value for the
proper refinement of the ingot structure.
particular type of steel shown in Table 3. Rockwell C tests
should be used where possible but light load tests may be
6. Chemical Composition
necessary on thin specimens. These tests should be specified by
6.1 An analysis of each heat of steel shall be made by the
agreement between seller and purchaser. The hardness value
manufacturer to determine the percentage of the elements
shall be obtained in accordance with the latest issue of Test
specified and these values shall conform to the chemical
Methods and Definitions A370, and shall be the average of at
composition specified in Table 1. If requested or required, the
least five readings taken in an area midway between the center
chemical composition shall be reported to the purchaser or his
and surface of the largest dimension of the cross-sectional
representative.
specimen or along the parallel surfaces of the longitudinal
6.2 Analysis may be made by the purchaser from finished specimen. The surface to be tested shall be ground sufficiently
bars and forgings by machining off the entire cross section and to remove any surface condition, scale, carburization, or
drilling parallel to the axis of the bar or forging at any point
decarburization which might affect readings.
A
TABLE 1 Chemical Composition, %
Man- Phos-
UNS Tung- Molyb-
Carbon Silicon Chromium Vanadium
Sulfur, Copper, Nickel,
ganese phorus,
Desig- Type Grade sten, denum,
max max max
max
nation max max
min max min max min max min max min max
B B
T72301 W1 A 0.10 0.40 0.10 0.40 0.030 0.030 . . . 0.15 . . . 0.10 0.15 0.10 0.20 0.20
B B
T72301 W1 C 0.10 0.40 0.10 0.40 0.030 0.030 . . . 0.30 . . . 0.10 0.15 0.10 0.20 0.20
C C
T72302 W2 A 0.10 0.40 0.10 0.40 0.030 0.030 . . . 0.15 0.15 0.35 0.15 0.10 0.20 0.20
C C
T72302 W2 C 0.10 0.40 0.10 0.40 0.030 0.030 . . . 0.30 0.15 0.35 0.15 0.10 0.20 0.20
T72305 W5 . 1.05 1.15 0.10 0.40 0.10 0.40 0.030 0.030 0.40 0.60 . . . 0.10 0.15 0.10 0.20 0.20
A
Chemistry limits include product analysis tolerances.
B
The carbon ranges for W1 and their respective suffix identification, sometimes referred to as tempers, are as follows:
Suffix Carbon Range, % Suffix Carbon Range, %
8 0.80–0.90 10 1.00–1.10
1 1
8 ⁄2 0.85–0.95 10 ⁄2 1.05–1.15
9 0.90–1.00 11 1.10–1.20
1 1
9 ⁄2 0.95–1.05 11 ⁄2 1.15–1.25
C
The carbon ranges for W2 and their respective suffix identification are as follows:
Suffix Carbon Range, %
8 ⁄2 0.85–0.95
9 0.90–1.00
9 ⁄2 0.95–1.10
13 1.30–1.50
A686 − 92 (2016)
TABLE 2 Maximum Brinell Hardness in Annealed or Cold Drawn
given in Tables 5-9 for the appropriate size and shape of
Condition
material. Lower limits of decarburization may be specified by
Type Annealed BHN Cold Drawn BHN
agreement between the seller and purchaser.
W1 202 241
W2 202 241 9.2 Material ordered as ground and polished or ground
W5 202 241
finished or machine finished shall be free of scale and
Drill Rod (W1, W2, or W5)
decarburization.
Ordered Diameter, in. (mm) Brinell Rockwell
To ⁄8 (3.2) HB 341 HRC 37
10. Permissible Variations for Dimensions
1 1
Over ⁄8 to ⁄4 (3.2 to 6.4), incl HB 275 HRC 28
1 1
Over ⁄4 to ⁄2 (6.4 to 12.7), incl HB 241 HRC 23
10.1 Permissible variations for dimensions shall not exceed
Over ⁄2 (12.7) HB 207 HRB 96
the applicable limits stated in Table 6, and Tables 10-22 and
Note 1.
NOTE 1—Unmachined tool steel forgings are furnished to size and
7.2.2 Hardness penetration and fracture grain size for Grade
surface allowances for machining and tolerances over allowances. Expe-
A shall be determined on test pieces of ⁄4 in. (19.1 mm)
rience indicates that the allowances and tolerances in the tabulation below
diameter and 3 in. (76.2 mm) length. Two pieces for each test
are satisfactory for many applications. When width and thickness differ,
each dimension carries its individual allowance and tolerance in accor-
shall be given a preliminary treatment by heating uniformly to
dance with the tabulation: also, the ID and OD take their respective
1600 6 10°F (871 6 5°C) and holding at temperature for
allowances and tolerances. When forgings are ordered, the purchaser
40 min, then quenching in oil. One piece shall be reheated to
should state whether the sizes are the forged or the finished sizes. The
1450 6 10°F (788 6 5°C) and the other to 1550 6 10°F
minimum sizes ordered for forgings should be the finished sizes plus
(843 6 5°C). Each piece shall be held in the furnace at the
allowances for machining; and the ordered forged sizes are subject to
applicable tolerances
respective temperature for 30 min and then quenched in brine
(5 to 10 % sodium chloride solution). The pieces shall be
10.2 Out-of-round tolerances for round bars shall be one
nicked with an abrasive wheel in the center of the length and
half the permissible dimensional variations stated in Table 6,
fractured. The fracture face of one portion of each broken test
Table 10, Table 12, Table 14, Table 15, and Table 17.
piece shall be ground smooth and etched in 1 + 1 muriatic acid
11. Workmanship, Finish, and Appearance
at 165°F (74°C) for measurement of the depth of penetration to
be expressed in 64ths of an inch. The fracture grain size shall
11.1 All carbon tool steels shall be free of heavy scale, deep
be determined on the remaining portion of each broken test
pitting, laps, porosity, injurious segregations, excessive non-
piece by comparison of the fracture surface of the hardened
metallic inclusions, seams, cracks, checks, slivers, scale marks,
case with the Shepherd Fracture Grain Size Standards. These
dents, soft and hard spots, pipes, or any defects that would
standards consist of ten pieces of steel with fracture faces
detrimentally affect the suitability of the material after removal
representing graduated grain sizes from the coarsest (No. 1) to
of the recommended stock allowance.
the finest (No. 10). The fracture grain size is estimated to the
12. Sampling
nearest quarter number. The hardness penetration and fracture
grain size for Grade A shall meet the requirements shown in
12.1 Each particular shipment of a heat of steel by type,
Table 3.
size, and shape shall be considered a lot and must conform to
the provisions of this specification.
8. Macrostructure
13. Inspection
8.1 The macrostructure of a specimen representing the
entire cross-sectional area in the annealed condition shall be
13.1 When specified in the purchase order, the inspector
prepared in accordance with the latest issue of Practice A561.
representing the purchaser shall have access to the material
It shall exhibit a structure free of excessive porosity,
subject to inspection for the purpose of witnessing the selection
segregation, slag, dirt or other nonmetallic inclusions, pipes,
of samples, preparation of test pieces, and performance of the
checks, cracks, and other injurious defects.
tests. For such tests, the inspector shall have the right to
indicate the pieces from which samples will be selected.
8.2 Macroetch severity levels for center porosity and ingot
Otherwise, the seller shall report to the purchaser, or his
pattern, illustrated photographically in Practice A561, shall not
representative, the results of the chemical analysis and the
exceed the ratings specification in Table 4 for the appropriate
physical and mechanical property tests made in accordance
material size and composition. More stringent requirements are
with this specification.
available by agreement between seller and purchaser.
14. Rejection and Rehearing
9. Decarburization
14.1 Unless otherwise specified, any rejections based on
9.1 Decarburization shall be determined on a specimen
tests made in accordance with this specification shall be
representing a cross section o
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: A686 − 92 (Reapproved 2010) A686 − 92 (Reapproved 2016)
Standard Specification for
Tool Steel, Carbon
This standard is issued under the fixed designation A686; 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 (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 This specification covers the chemical, mechanical, and physical requirements for available wrought carbon tool steel
products.
1.2 These products, which include hot- or cold-finished bar, plate, sheet, 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 mathematical
conversions to SI units that are provided for information only.only and are not considered standard.
2. Referenced Documents
2.1 ASTM Standards:
A370 Test Methods and Definitions for Mechanical Testing of Steel Products
A388/A388M Practice for Ultrasonic Examination of Steel Forgings
A561 Practice for Macroetch Testing of Tool Steel Bars
A700 Guide for Packaging, Marking, and Loading Methods for Steel Products for Shipment
E3 Guide for Preparation of Metallographic Specimens
E30 Test Methods for Chemical Analysis of Steel, Cast Iron, Open-Hearth Iron, and Wrought Iron (Withdrawn 1995)
E45 Test Methods for Determining the Inclusion Content of Steel
E59 Practice for Sampling Steel and Iron for Determination of Chemical Composition (Withdrawn 1996)
2.2 Military Standard:
MIL-STD-163 Steel Mill Products, Preparation for Shipment and Storage
2.3 Federal Standards:
Fed. Std. No. 123 Marking for Shipment (Civil Agencies)
Fed. Std. No. 183 Continuous Identification Marking of Iron and Steel Products
3. Classification
3.1 Material in accordance with this specification is classified by chemical composition. Types correspond to respective AISI
designations.
3.1.1 Carbon Tool Steels, Identification W—Types W1, W2, and W5 are often referred to as water hardening tool steels since
they require rapid quenching rates to attain the necessary hardness. Except in very small sizes they will harden with a hard case
and a soft core.
3.1.1.1 Type W1 is an unalloyed carbon steel available in several carbon ranges.
3.1.1.2 Type W2 is characterized by a nominal vanadium content of 0.25 % and is also available in several carbon ranges.
3.1.1.3 Type W5 is characterized by a nominal chromium content of 0.50 %.
This specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.29
on Tool Steels.
Current edition approved Oct. 1, 2010March 1, 2016. Published December 2010June 2016. Originally approved in 1973. Last previous edition approved in 20042010 as
A686 – 92 (2010). (2004). DOI: 10.1520/A0686-92R10. 10.1520/A0686-92R16.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Available from Standardization Documents Order Desk, Bldg. 4 Section D, DLA Document Services, Building 4/D, 700 Robbins Ave., Philadelphia, PA 19111-5094,
Attn: NPODS.http://quicksearch.dla.mil.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A686 − 92 (2016)
3.1.1.4 A suffix following the type designation is added to denote the minimum carbon content of the carbon range to be
specified.
3.1.2 Types W1 and W2 are further classified by quality levels, namely, Grade A and Grade C.
3.1.2.1 Grade A is sometimes referred to as Extra or Special. It is controlled for hardenability; the chemical composition is held
to closest limits; and it is subject to rigid tests to ensure uniformity. Grade A is available with three degrees of hardenability,
namely, shallow hardening, regular hardening, and deep hardening.
3.1.2.2 Grade C is sometimes referred to as Regular or Standard. It is intended for applications that do not require controlled
hardenability and where some latitude in uniformity is permissible.
4. Ordering Information
4.1 Orders for material under this specification shall include the following information, as required to describe adequately the
desired material:
4.1.1 Class of material (carbon tool steel),
4.1.2 Type (W1, W2, W5),
4.1.3 Suffix denoting carbon range (where applicable, such as W1–9, W2–10, etc.),
4.1.4 Grade and hardenability (where applicable, for example, Grade A deep hardening, and so forth),
4.1.5 Shape (sheet, plate, flat bar, round bar, square bar, hexagon bar, octagon, special shapes),
4.1.6 Dimensions (thickness, width, diameter, length),
4.1.7 Finish (hot rolled, forged, blasted or pickled, cold drawn, machined, ground, precision ground and polished),
4.1.8 Condition (annealed, unannealed, hardened and tempered, and so forth),
4.1.9 ASTM specification number and date of issue, and
4.1.10 Special requirements.
5. Materials and Manufacture
5.1 Unless otherwise specified, material covered by this specification shall be made by an electric melting process. It shall be
made from ingots that have been reduced in cross section in such a manner and to such a degree as to ensure proper refinement
of the ingot structure.
6. Chemical Composition
6.1 An analysis of each heat of steel shall be made by the manufacturer to determine the percentage of the elements specified
and these values shall conform to the chemical composition specified in Table 1. If requested or required, the chemical composition
shall be reported to the purchaser or his representative.
6.2 Analysis may be made by the purchaser from finished bars and forgings by machining off the entire cross section and drilling
parallel to the axis of the bar or forging at any point midway between the center and surface in accordance with the latest issue
of Practice E59. The chemical analysis of the drilling chips shall be made in accordance with the latest issue of Test Methods E30.
The chemical composition thus determined shall not vary from the limits specified in Table 1.
A
TABLE 1 Chemical Composition, %
UNS Type Grade Carbon Man- Silicon Phos- Sulfur, Chromium Vanadium Tung- Molyb- Copper, Nickel,
Desig- ganese phorus, max sten, denum, max max
nation max max max
min max min max min max min max min max
B B
T72301 W1 A 0.10 0.40 0.10 0.40 0.030 0.030 . . . 0.15 . . . 0.10 0.15 0.10 0.20 0.20
B B
T72301 W1 C 0.10 0.40 0.10 0.40 0.030 0.030 . . . 0.30 . . . 0.10 0.15 0.10 0.20 0.20
C C
T72302 W2 A 0.10 0.40 0.10 0.40 0.030 0.030 . . . 0.15 0.15 0.35 0.15 0.10 0.20 0.20
C C
T72302 W2 C 0.10 0.40 0.10 0.40 0.030 0.030 . . . 0.30 0.15 0.35 0.15 0.10 0.20 0.20
T72305 W5 . 1.05 1.15 0.10 0.40 0.10 0.40 0.030 0.030 0.40 0.60 . . . 0.10 0.15 0.10 0.20 0.20
A
Chemistry limits include product analysis tolerances.
B
The carbon ranges for W1 and their respective suffix identification, sometimes referred to as tempers, are as follows:
Suffix Carbon Range, % Suffix Carbon Range, %
8 0.80–0.90 10 1.00–1.10
1 1
8 ⁄2 0.85–0.95 10 ⁄2 1.05–1.15
9 0.90–1.00 11 1.10–1.20
1 1
9 ⁄2 0.95–1.05 11 ⁄2 1.15–1.25
C
The carbon ranges for W2 and their respective suffix identification are as follows:
Suffix Carbon Range, %
8 ⁄2 0.85–0.95
9 0.90–1.00
9 ⁄2 0.95–1.10
13 1.30–1.50
A686 − 92 (2016)
7. Hardness Properties
7.1 Annealed hardness values shall be obtained in accordance with the latest issue of Test Methods and Definitions A370, and
shall not exceed the Brinell hardness values (or equivalent Rockwell hardness values) specified in Table 2.
7.2 Specimens for determination of minimum response to hardening shall be ¼-in. (6.4-mm) thick disks cut so as to represent
either the full cross-sectional area or that midway between the center and outer surface of the material. If the material form or size
does not lend itself to accurate hardness determination on ¼-in. (6.4-mm) thick cross-sectional disks, then longitudinal specimens
may be used for hardness testing. Examples are round bars less than ⁄2 in. (12.7 mm) in diameter or sheet. In this case, the
specimen shall be a minimum of 3 in. (76.2 mm) in length and parallel flats shall be ground on the original mill surfaces. The
specimens shall be heat treated as prescribed in Table 3.
7.2.1 The hardness of the specimen after the specified heat treatment shall meet the minimum hardness value for the particular
type of steel shown in Table 3. Rockwell C tests should be used where possible but light load tests may be necessary on thin
specimens. These tests should be specified by agreement between seller and purchaser. The hardness value shall be obtained in
accordance with the latest issue of Test Methods and Definitions A370, and shall be the average of at least five readings taken in
an area midway between the center and surface of the largest dimension of the cross-sectional specimen or along the parallel
surfaces of the longitudinal specimen. The surface to be tested shall be ground sufficiently to remove any surface condition, scale,
carburization, or decarburization which might affect readings.
7.2.2 Hardness penetration and fracture grain size for Grade A shall be determined on test pieces of ⁄4 in. (19.1 mm) diameter
and 3 in. (76.2 mm) length. Two pieces for each test shall be given a preliminary treatment by heating uniformly to 1600 6 10°F
(871 6 5°C) and holding at temperature for 40 min, 40 min, then quenching in oil. One piece shall be reheated to 1450 6 10°F
1450 6 10°F (788 6 5°C) and the other to 15506 10°F (843 6 1550 6 10°F (843 6 5°C). Each piece shall be held in the furnace
at the respective temperature for 30 min and then quenched in brine (5 to 10 % sodium chloride solution). The pieces shall be
nicked with an abrasive wheel in the center of the length and fractured. The fracture face of one portion of each broken test piece
shall be ground smooth and etched in 1 + 1 muriatic acid at 165°F (74°C) for measurement of the depth of penetration to be
expressed in 64ths of an inch. The fracture grain size shall be determined on the remaining portion of each broken test piece by
comparison of the fracture surface of the hardened case with the Shepherd Fracture Grain Size Standards. These standards consist
of ten pieces of steel with fracture faces representing graduated grain sizes from the coarsest (No. 1) to the finest (No. 10). The
fracture grain size is estimated to the nearest quarter number. The hardness penetration and fracture grain size for Grade A shall
meet the requirements shown in Table 3.
8. Macrostructure
8.1 The macrostructure of a specimen representing the entire cross-sectional area in the annealed condition shall be prepared
in accordance with the latest issue of Practice A561. It shall exhibit a structure free of excessive porosity, segregation, slag, dirt
or other nonmetallic inclusions, pipes, checks, cracks, and other injurious defects.
8.2 Macroetch severity levels for center porosity and ingot pattern, illustrated photographically in Practice A561, shall not
exceed the ratings specification in Table 4 for the appropriate material size and composition. More stringent requirements are
available by agreement between seller and purchaser.
9. Decarburization
9.1 Decarburization shall be determined on a specimen representing a cross section of the material and prepared in accordance
with the latest issue of Guide E3. When examined at 20× or greater magnification it shall not exceed the values given in Tables
5-9 for the appropriate size and shape of material. Lower limits of decarburization may be specified by agreement between the
seller and purchaser.
9.2 Material ordered as ground and polished or ground finished or machine finished shall be free of scale and decarburization.
The Shepherd Fracture GrainGain Size Standards may be purchased from Metallurgical Services, Inc., Box 1075, 925 Main St., Niagara Falls, NY 14302.
TABLE 2 Maximum Brinell Hardness in Annealed or Cold Drawn
Condition
Type Annealed BHN Cold Drawn BHN
W1 202 241
W2 202 241
W5 202 241
Drill Rod (W1, W2, or W5)
Ordered Diameter, in. (mm) Brinell Rockwell
To ⁄8 (3.2) HB 341 HRC 37
1 1
Over ⁄8 to ⁄4 (3.2 to 6.4), incl HB 275 HRC 28
1 1
Over ⁄4 to ⁄2 (6.4 to 12.7), incl HB 241 HRC 23
Over ⁄2 (12.7) HB 207 HRB 96
A686 − 92 (2016)
TABLE 3 Heat-Treating Requirements
Type Carbon Range, % Austenitizing Temperature, Quench Medium Minimum
°F (°C) Hardness,
HRC
W1 0.70–0.85 1475 (802) brine 64
0.85–0.95 1475 (802) brine 65
0.95–1.50 1450 (788) brine 65
W2 0.85–0.95 1475 (802) brine 65
0.95–1.50 1450 (788) brine 65
W5 1.05–1.15 1475 (802) brine 65
Hardness Penetration and Fracture Grain Size for Grade A
A A
Specified Quench W1 (0.70 to 0.95 C) W2 (0.85 to 0.95 C) W1 (0.95 to 1.10 C) W1 (1.10 to 1.30 C)
A
Depth of Temperature, W2 (0.95 to 1.10 C)
Hardening ° F (°C) Penetration 64th in. Grain Size Penetration 64th in. Grain Size
(Shepherd) Not (Shepherd) Not
Coarser Than Coarser Than
Shallow 1450 (788) 10 max 8 8 max 8 ⁄2
5 1 5 1
1550 (843) not more than ⁄64 deeper 6 ⁄2 not more than ⁄64 deeper 6 ⁄2
than at 1450 than at 1450
Regular 1450 (788) 9 to 13 8 7 to 11 8 ⁄2
8 1 8 1
1550 (843) not more than ⁄64 deeper 6 ⁄2 not more than ⁄64 deeper 6 ⁄2
than at 1450 than at 1450
Deep 1450 (788) 12 min 8 10 to 16 8
10 1 10 1
1550 (843) not more than ⁄64 deeper 6 ⁄2 not more than ⁄64 deeper 6 ⁄2
than at 1450 than at 1450
TABLE 3 Heat-Treating Requirements
Minimum
Austenitizing Temperature,
Type Carbon Range, % Quench Medium Hardness,
°F (°C)
HRC
W1 0.70–0.85 1475 (802) brine 64
0.85–0.95 1475 (802) brine 65
0.95–1.50 1450 (788) brine 65
W2 0.85–0.95 1475 (802) brine 65
0.95–1.50 1450 (788) brine 65
W5 1.05–1.15 1475 (802) brine 65
Hardness Penetration and Fracture Grain Size for Grade A
W1 (0.95 to 1.10 C)
A A
W1 (0.70 to 0.95 C) W2 (0.85 to 0.95 C) W1 (1.10 to 1.30 C)
A
...