ISO 683-2:2012

Heat-treatable steels, alloy steels and free-cutting steels - Part 2: Alloy steels for quenching and tempering

ISO 683-2:2012 specifies the technical delivery requirements for semi-finished products, hot formed (e.g. blooms, billets, slabs), bars, wire rod, finished flat products and hammer or drop forgings manufactured from the direct-hardening alloy steels and the alloy flame and induction hardening steels listed (in Table 3) and supplied in one of the heat-treatment conditions given for the different types of products (in Table 1) and in one of the surface conditions given (in Table 2). The steels are, in general, intended for the manufacture of quenched and tempered or austempered and flame- or induction-hardened machine parts. The requirements for mechanical properties given in ISO 683-2:2012 are restricted to the sizes given (in Table 8). In addition to ISO 683-2:2012, the general technical delivery requirements of ISO 404 are applicable.

Aciers pour traitement thermique, aciers alliés et aciers pour décolletage — Partie 2: Aciers alliés pour trempe et revenu

General Information

• Status: Withdrawn
• Publication Date: 19-Sep-2012
• Withdrawal Date: 19-Sep-2012
• ICS: 77.140.10 - Heat-treatable steels
• ICS: 77.140.20 - Stainless steels
• ICS: 77.140.45 - Non-alloyed steels
• Technical Committee: ISO/TC 17/SC 4 - Heat treatable and alloy steels
• Drafting Committee: ISO/TC 17/SC 4 - Heat treatable and alloy steels
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 29-Jun-2016
• Completion Date: 13-Dec-2025

Relations

• Revised: ISO 683-2:2016 - Heat-treatable steels, alloy steels and free-cutting steels - Part 2: Alloy steels for quenching and tempering
• Effective Date: 23-Jan-2016
• Revises: ISO/TR 11637:1997 - Boron treated engineering steels for quenching and tempering
• Effective Date: 19-May-2012
• Revises: ISO 683-1:1987 - Heat-treatable steels, alloy steels and free-cutting steels - Part 1: Direct-hardening unalloyed and low-alloyed wrought steel in form of different black products
• Effective Date: 11-Apr-2009

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 683-2
First edition
2012-09-15
Heat-treatable steels, alloy steels and
free-cutting steels —
Part 2:
Alloy steels for quenching and tempering
Aciers pour traitement thermique, aciers alliés et aciers pour
décolletage —
Partie 2: Aciers alliés pour trempe et revenu
Reference number
©
ISO 2012
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s
member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
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Published in Switzerland
ii © ISO 2012 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Classification and designation . 3
4.1 Classification . 3
4.2 Designation . 3
5 Information to be supplied by the purchaser . 3
5.1 Mandatory information . 3
5.2 Options and/or supplementary or special requirements . 3
6 Manufacturing process . 4
6.1 General . 4
6.2 Deoxidation . 4
6.3 Heat-treatment condition and surface condition at delivery . 4
6.4 Traceability of the cast . 4
7 Requirements . 5
7.1 Chemical composition, mechanical properties and hardenability . 5
7.2 Machinability . 5
7.3 Cold shearability . 5
7.4 Grain size . 6
7.5 Non-metallic inclusions . 6
7.6 Internal soundness . 6
7.7 Surface quality . 6
7.8 Decarburization . 6
7.9 Shape, dimensions and tolerances . 7
8 Inspection . 7
8.1 Testing procedures and types of documents . 7
8.2 Frequency of testing . 7
8.3 Specific inspection and testing . 7
9 Test methods . 8
9.1 Chemical analysis . 8
9.2 Mechanical tests . 8
9.3 Hardness and hardenability tests . 8
9.4 Retests . 9
10 Marking . 9
Annex A (normative) Ruling sections for mechanical properties .34
Annex B (normative) Supplementary or special requirements .37
Annex C (informative) Designation of steels given in this part of ISO 683 and of comparable grades
covered in various designation systems .39
Annex D (informative) Dimensional standards applicable to products complying with this part of
ISO 683 .41
Bibliography .42
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International
Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 683-2 was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 4, Heat treatable and
alloy steels.
This first edition cancels and replaces the first edition of ISO 683-1:1987 and ISO/TR 11637:1997, which have
been technically revised.
ISO 683 consists of the following parts, under the general title Heat-treatable steels, alloy steels and free-
cutting steels:
— Part 1: Non-alloy steels for quenching and tempering
— Part 2: Alloy steels for quenching and tempering
— Part 9: Wrought free-cutting steels
— Part 10: Wrought nitriding steels
— Part 11: Case-hardening steels
— Part 14: Hot-rolled steels for quenched and tempered springs
— Part 15: Valve steels for internal combustion engines
— Part 17: Ball and roller bearing steels
— Part 18: Bright products of unalloyed and low alloy steels
iv © ISO 2012 – All rights reserved

INTERNATIONAL STANDARD ISO 683-2:2012(E)
Heat-treatable steels, alloy steels and free-cutting steels —
Part 2:
Alloy steels for quenching and tempering
1 Scope
1.1 This part of ISO 683 specifies the technical delivery requirements for
— semi-finished products, hot formed, e.g. blooms, billets, slabs (see Note 1),
— bars (see Note 1),
— wire rod,
— finished flat products, and
— hammer or drop forgings (see Note 1)
manufactured from the direct hardening alloy steels and the alloy flame- and induction-hardening steels listed
in Table 3 and supplied in one of the heat-treatment conditions given for the different types of products in Table
1 and in one of the surface conditions given in Table 2.
The steels are, in general, intended for the manufacture of quenched and tempered or austempered (see 3.2
and Note 2) and flame- or induction-hardened machine parts (see Tables 8 and 9).
The requirements for mechanical properties given in this part of ISO 683 are restricted to the sizes given in the
relevant Table 8.
NOTE 1 Hammer-forged semi-finished products (blooms, billets, slabs, etc.), seamless rolled rings and hammer-forged
bars are in the following covered under semi-finished products or bars and not under the term “hammer and drop forgings”.
NOTE 2 For the purposes of simplification, the term “quenched and tempered” is, unless otherwise indicated, used in
the following also for the austempered condition.
NOTE 3 For International Standards relating to steels complying with the requirements for the chemical composition
in Table 3, however, supplied in other product forms or treatment conditions than given above or intended for special
applications, and for other related International Standards, see the Bibliography.
NOTE 4 This part of ISO 683 does not apply to bright products and bars and wire rod for cold heading. For such
products, see ISO 683-18 and ISO 4954.
1.2 In special cases, variations in these technical delivery requirements or additions to them can form the
subject of an agreement at the time of enquiry and order (see Annex B).
1.3 In addition to this part of ISO 683, the general technical delivery requirements of ISO 404 are applicable.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
ISO 148-1, Metallic materials — Charpy pendulum impact test — Part 1: Test method
ISO 377, Steel and steel products — Location and preparation of samples and test pieces for mechanical testing
ISO 404, Steel and steel products — General technical delivery requirements
ISO 642, Steel — Hardenability test by end quenching (Jominy test)
ISO 643, Steels – Micrographic determination of the apparent grain size
ISO 3887, Steels — Determination of depth of decarburization
ISO 4885, Ferrous products — Heat treatments — Vocabulary
ISO 4948-1, Steels; Classification —Part 1: Classification of steels into unalloyed and alloy steels based on
chemical composition
ISO 4948-2, Steels; Classification — Part 2: Classification of unalloyed and alloy steels according to main
quality classes and main property or application characteristics
ISO/TS 4949, Steel names based on letter symbols
ISO 4967, Steel — Determination of content of non metallic inclusions — Micrographic method using
standard diagrams.
ISO 6506-1, Metallic materials — Brinell hardness test — Part 1: Test method
ISO 6508-1, Metallic materials — Rockwell hardness test — Part 1: Test method (scales A, B, C, D, E, F,
G, H, K, N, T)
ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
ISO 6929, Steel products — Vocabulary
ISO 7788, Steel — Surface finish of hot-rolled plates and wide flats — Delivery requirements
ISO 9443, Heat-treatable and alloy steels — Surface quality classes for hot-rolled round bars and wire rods —
Technical delivery conditions
ISO/TR 9769, Steel and Iron — Review of available methods of analysis
ISO 10474, Metallic products — Inspection documents
ISO 14284, Steel and iron — Sampling and preparation of samples for the determination of chemical composition
3 Terms and definitions
For the purposes of this document, the definitions of ISO 377, ISO 4885, ISO 4948-1, ISO 4948-2, ISO 6929,
ISO 14284 and the following apply.
NOTE For deviations from these terms and definitions, see Notes 1 and 2 to the Scope.
3.1
ruling section
section for which the specified mechanical properties shall apply
NOTE Independent of the actual shape and dimensions of the cross-section of the product, the size of its ruling
section is always given by a diameter. This corresponds to the diameter of an “equivalent round bar”. That is, a round bar
which, at the position of its cross-section specified for taking the test pieces for the mechanical tests, will, when being
cooled from austenitizing temperature, shows the same cooling rate as the actual ruling section of the product concerned
at its position for taking the test pieces.
2 © ISO 2012 – All rights reserved

3.2
austempering
austenitization of a steel with a subsequent cooling to a temperature in the Bainite region and holding at this
temperature until a desired degree of transformation is obtained
NOTE The subsequent cooling to room temperature can be carried out in any manner desired.
3.3
alloy steel
non-alloy steel as defined in ISO 4948-1
3.4
special
special steel as defined in ISO 4948-2
4 Classification and designation
4.1 Classification
The classification of the relevant steel grades is according to ISO 4948-1 and ISO 4948-2. All steel grades
covered by this part of ISO 683 are alloy special steels.
4.2 Designation
For the steel grades covered by this part of ISO 683, the steel names as given in the relevant tables are
allocated in accordance with ISO/TS 4949.
5 Information to be supplied by the purchaser
5.1 Mandatory information
The manufacturer shall obtain the following information from the purchaser at the time of enquiry and order:
a) the quantity to be delivered;
b) the designation of the product form (slab, bloom, billet, round bar, wire rod, wide flat, sheet, plate, strip,
forging, etc.);
c) either the designation of the dimensional standard and the dimensions and tolerances selected from this
(see 7.9) or, for example in the case of drop forgings, the designation of the drawing or any other document
covering the dimensions and tolerances required for the product;
d) reference to this part of ISO 683, i.e. ISO 683-2;
e) the designation of the steel grade given in Table 3;
f) the symbol for the required heat-treatment condition (see Table 1, column 2);
g) standard designation for a test report 2.2 or, if required any other type of inspection document in accordance
with ISO 10474 or according to another regional standard, e.g. EN 10204 or JIS G 0415.
5.2 Options and/or supplementary or special requirements
A number of options are specified in this part of ISO 683 and listed below. If the purchaser does not indicate the
wish to implement any of these options, the products will be supplied in accordance with the basic specifications
of this part of ISO 683 (see 5.1):
a) if another surface condition than “hot worked” or a special surface quality is required, the surface condition
(see Table 2) and the surface quality (see 7.7);
b) any requirement for the hardenability (+H, +HH, +HL) for special steels (see 7.1.4 and Tables 5 to 7);
c) any supplementary requirement that shall be complied with, the symbol and, where necessary, the details
of this supplementary requirement (see Annex B);
d) any requirement for the verification of non-metallic inclusion content (see 7.5);
e) verification of hardenability and, if agreed, the information about calculation of the hardenability (see 9.3.2);
f) any requirement regarding the permissible depth of decarburization (see 7.8);
g) suitability of bars and rod for bright drawing (see 7.7.4);
h) any requirement relating to the removal of surface defects (see 7.7.5).
EXAMPLE 50 hot-rolled round bars according to ISO 1035-1 with a nominal diameter of 40 mm and a nominal length
of 8 000 mm with diameter tolerance according to class S and with length tolerance according to class L2 of ISO 1035-4
made of steel grade ISO 683-2 42CrMo4 (see Table 3) in the heat-treatment condition +S (see Table 1), surface blast
cleaned (+BC) (see Table 2), cast analysis/option B.5 with an inspection certificate 3.1 according to ISO 10474
50 round bars ISO 1035 - 40,0S × 8 000L2
ISO 683-2 - 42CrMo4+S +BC option B.5
ISO 10474 - 3.1
6 Manufacturing process
6.1 General
The manufacturing process of the steel and of the products is, with the restrictions given by the requirements
in 6.2 to 6.4, left to the discretion of the manufacturer.
For minimum reduction ratio or minimum thickness deformation ratio of rolled and forged products, see B.5.
6.2 Deoxidation
All steels shall be deoxidized.
6.3 Heat-treatment condition and surface condition at delivery
6.3.1 Heat-treatment condition
The products shall be delivered in one of the heat-treatment conditions given in Table 1, lines 2 to 6 as agreed
during time of enquiry and order.
6.3.2 Particular surface conditions
If so agreed at the time of enquiry and order, the products shall be delivered in one of the particular surface
conditions given in Table 2, lines 3 to 6.
6.4 Traceability of the cast
Each product shall be traceable to the cast (see Clause 10).
4 © ISO 2012 – All rights reserved

7 Requirements
7.1 Chemical composition, mechanical properties and hardenability
7.1.1 General
Table 1 shows the combinations of usual heat-treatment conditions at delivery, product forms and requirements,
as specified in Tables 3 to 9.
Except where steels are ordered in the quenched and tempered condition, this part of ISO 683 makes for the
alloyed steels provisions to be supplied with or without hardenability requirements (see Table 1, columns 8 and 9).
7.1.2 Chemical composition
The chemical composition determined by cast analysis shall comply with the values in Table 3.
Permissible deviations between the limiting values for cast analysis and the values for product analysis are
given in Table 4.
The product analysis shall be carried out when specified at the time of the enquiry and order (see B.4).
7.1.3 Mechanical properties
Where the steel is ordered without hardenability requirements, the requirements for mechanical properties
specified in Tables 7 or 8 apply as appropriate for the particular heat treatment condition.
In this case, the hardenability values given in Table 5 are for guidance purposes only.
The mechanical property values given in Table 8 apply to test pieces in the quenched and tempered condition,
which have been taken and prepared in accordance with Figure 2 or Figures 3 and 4 (see also footnote a to Table 1).
7.1.4 Hardenability
Where the steel is ordered using the designations given in Table 5 or 6 to normal (see Table 5) or to narrowed
(see Table 6) hardenability requirements, the values of hardenability given in Table 5 or 6, respectively apply in
addition to the requirements cited in Table 1, columns 9.1 and 9.2. (See footnote b to Table 3.)
7.1.5 Surface hardness
For the surface hardness of alloy steels after flame or induction hardening, the specifications in Table 9 apply.
7.2 Machinability
All steels are machinable in the condition “soft annealed”. Where improved machinability is required, grades
with a specified sulfur range and/or with a specific treatment should be ordered to improve machinability (see
also Table 1, line 6).
7.3 Cold shearability
7.3.1 Under suitable shearing conditions (avoiding local stress peaks, preheating, application of blades with
a profile adapted to that of the product, etc.) all steels are cold shearable in the soft annealed (+A) condition.
7.3.2 Steel grades 34Cr4, 37Cr4, 41Cr4, 25CrMo4, 34CrMo4, 42CrMo4 and 41CrNiMo2 with maximum and
specified range S-content, boron-alloy steel grades 33MnCrB5-2 and 39MnCrB6-2 and the corresponding +H,
+HH and +HL grades (see Tables 3 and 5 to 7) are, under suitable conditions, also cold shearable when being
delivered in the condition “treated to improve shearability (+S)” with the hardness requirements given in Table 7.
7.3.3 Under suitable conditions, steel grades 20MnB5, 30MnB5, 39MnB5 and 27MnCrB5-2, and the corresponding
grades with requirements on hardenability (see Table 5), are cold shearable in the untreated condition.
7.4 Grain size
All steels shall have a fine grain structure with an austenite grain size of 5 or finer when tested in accordance
with ISO 643. For verification, see B.2.
7.5 Non-metallic inclusions
7.5.1 Microscopic inclusions
The special steels shall have a certain degree of cleanness; however, verification of the non-metallic inclusion
content requires a special agreement. If there is such an agreement at the time of enquiry and order, the
microscopic non-metallic inclusion content shall be determined to an agreed procedure and within agreed
limits in accordance with ISO 4967 or another standard, e.g. regional standards EN 10247 or JIS G 0555.
For grades with specified minimum sulfur content, the agreement should not include sulfides.
7.5.2 Macroscopic inclusions
This requirement is applicable to the verification of the macroscopic inclusions in special steels. If verification
is agreed, the method and acceptance limits shall be agreed at the time of enquiry and order.
7.6 Internal soundness
Where appropriate, requirements relating to the internal soundness of the products shall be agreed at the time
of enquiry and order (see B.3).
7.7 Surface quality
7.7.1 All products shall have a smooth surface finish appropriate to the manufacturing process applied.
7.7.2 Minor surface imperfections, which may occur also under normal manufacturing conditions, such as
prints originating from rolled-in scale, are not to be regarded as defects.
7.7.3 Bars and wire rod are delivered with surface class A according to ISO 9443 and hot-rolled plates and wide
flats are delivered with a surface according ISO 7788 unless otherwise agreed at the time of enquiry and order.
Where no International Standard on the surface quality of steel products exists, detailed requirements referring
to this characteristic shall, where appropriate, be agreed at the time of enquiry and order.
It is more difficult to detect and eliminate surface discontinuities from coiled products than from cut lengths.
This should be taken into account when agreements on surface quality are made.
7.7.4 If suitability of bars and rod for bright drawing is required, this shall be agreed at the time of enquiry and order.
7.7.5 The removal of surface defects by welding shall only be permitted with the approval of the customer or
his/her representative.
If surface discontinuities are repaired, the method and maximum depth of removal shall be agreed at the time
of enquiry and order.
7.8 Decarburization
Requirements relating to the permissible depth of decarburization may be agreed at the time of enquiry and order.
6 © ISO 2012 – All rights reserved

The depth of decarburization shall be determined in accordance with the micrographic method specified in ISO 3887.
7.9 Shape, dimensions and tolerances
The shape, dimensions and tolerances of the products shall comply with the requirements agreed at the time
of enquiry and order. The agreements shall, as far as possible, be based on corresponding International
Standards (see Annex D); otherwise on suitable national standards.
8 Inspection
8.1 Testing procedures and types of documents
8.1.1 Products complying with this part of ISO 683 shall be ordered and delivered with one of the inspection
documents as specified in ISO 10474 or another standard, e.g. regional standards EN 10204 or JIS G 0415.
The type of document shall be agreed upon at the time of enquiry and order. If the order does not contain any
specification of this type, a test report 2.2 shall be issued.
8.1.2 If, in accordance with the agreements made at the time of enquiry and order, a test report 2.2 is to be
provided, this shall cover the following information:
a) confirmation that the material complies with the requirements of the order;
b) results of the cast analysis for all elements specified in Table 3 for the steel grade concerned.
8.1.3 If, in accordance with the agreements in the order, an inspection certificate 3.1 or 3.2, is to be provided,
the specific inspections and tests described in 8.3 and Clause 9 shall be carried out and the results shall be
confirmed in the inspection certificate.
In addition, the inspection certificate shall cover:
a) confirmation that the material complies with the requirements of the order;
b) results of the cast analysis for all elements specified in Table 3 for the steel grade concerned;
c) results of all inspections and tests ordered by supplementary requirements (see Annex B);
d) the symbol, letters or numbers relating the inspection certificate, test pieces and products to each other.
8.2 Frequency of testing
The amount of testing, the sampling conditions and the test methods to be applied for the verification of the
requirements shall be in accordance with the prescriptions of Table 10.
8.3 Specific inspection and testing
8.3.1 Verification of the hardenability, hardness and mechanical properties
For steels being ordered without hardenability requirements, i.e. without the symbol, +H, +HH or +HL in the
designation, the hardness requirements or mechanical properties given for the relevant heat-treatment condition
in Table 1, column 8, subclause 2, shall, with the following exception, be verified. The requirements given in
Table 1, footnote a (mechanical properties of reference test pieces), shall only be verified if supplementary
requirement specified in B.1 is ordered.
For steels being ordered with the symbol +H, +HH or +HL in the designation (see Tables 5 and 6), unless
otherwise agreed, only the hardenability requirements according to Table 5 or 6 are to be verified.
8.3.2 Visual and dimensional inspection
A sufficient number of products shall be inspected to ensure the compliance with the specification.
9 Test methods
9.1 Chemical analysis
The choice of a suitable physical or chemical analytical method for the analysis shall be at the discretion of the
manufacturer. In cases of dispute, the method for product analysis used shall be agreed taking into account the
relevant existing International Standards.
NOTE The list of available International Standards on chemical analysis is given in ISO/TR 9769.
9.2 Mechanical tests
9.2.1 Tensile test
The tensile test shall be carried out in accordance with ISO 6892-1.
For the specified yield strength in the tables on mechanical properties in this part of ISO 683, the upper yield
strength, R , shall be determined.
eH
If a yield phenomenon is not present, the 0,2 % proof strength, R , shall be determined.
p0,2
9.2.2 Impact test
The impact test shall be carried out in accordance with ISO 148-1.
At the time of enquiry and order, additional requirements concerning the impact energy and the verification at
temperatures other than room temperature (0 °C, –20 °C and –40 °C) can be agreed.
NOTE Impact values at lower temperatures cannot be achieved for all steel grades.
The average values of a set of three test pieces shall be equal to or greater than the specified value. One
individual value may be below the specified value, provided it is not less than 70 % of that value.
If these conditions are not satisfied, the sample product is rejected and retests may be carried out on the
remainder of the test unit.
9.3 Hardness and hardenability tests
9.3.1 Hardness in treatment conditions +A and +S
For products in treatment conditions +A (soft annealed) and +S (treated to improve shearability), the hardness
shall be measured in accordance with ISO 6506-1.
9.3.2 Verification of hardenability
As far as available, the manufacturer has the option to verify the hardenability by calculation. The calculation
method is left to the discretion of the manufacturer. If agreed at the time of enquiry and order, the manufacturer
shall give sufficient information about the calculation for the customer to confirm the result.
If a calculation formula is not available or in the case of dispute, an end quench hardenability test shall be
carried out in accordance with ISO 642. The temperature for quenching shall comply with the relevant tables
in this part of ISO 683. The hardness values shall be determined in accordance with ISO 6508-1, scale C.
8 © ISO 2012 – All rights reserved

9.3.3 Surface hardness
The surface hardness of steels after flame and induction hardening (see Table 9) shall be determined in
accordance with ISO 6508-1, scale C.
9.4 Retests
Retests for steels for quenching and tempering and criteria should be as specified in ISO 404.
10 Marking
The manufacturer shall mark the products or the bundles or boxes containing the products in a suitable way, so
that the identification of the cast, the steel type and the origin of the delivery is possible (see B.6).
Table 1 — Combinations of usual heat-treatment conditions at delivery, product forms and
requirements according to Tables 3 to 9
No. 1 2 3 4 5 6 7 8 9
Applicable requirements if the steel is ordered with the
designation given in
Heat-
x indicates applicable to
treatment
Sym- Table 3 Table 5 or 6
1 condition
bol
at
Semi- Hammer
Wire Flat
delivery
finished Bars and drop 8.1 8.2 9.1 9.2 9.3
rod product
products forgings
Un- None
a
2 x x x x x –
treated or +U
Harden-
Treated
ability
As in
to Table 7
Chemical
values
column
3 improve +S x x – – – column
compo-
accord-
Maximum a 8.1 and
shear- +S
sition
ing to
hardness 8.2
ability
accor-
Table 5
according to (see
ding to
or 6
Table 7
footnote
Soft
Tables 3
4 +A x x x X x column
b to
annealed
and 4 a
+A
Table 3
Quench- Mechanical
Not applic-
5 ed and +QT – x – x x properties Table 8
able
tempered according to
Other treatment conditions, for example certain annealing conditions to achieve a certain structure, may be agreed at the time of
6 Others enquiry and order. The condition “annealed to achieve a spheroidization of the carbides” , as required for cold heading and cold
extrusion, is covered in ISO 4954.
a
The mechanical properties specified in Table 8 for the quenched and tempered condition shall be achievable after appropriate heat treatment if so
agreed at the time of enquiry and order (for reference test pieces, see B.1).
Table 2 — Surface condition at delivery
No. 1 2 3 4 5 6 7 8 9
x indicates in general applicable to
Semi-
Hammer
finished
Surface condition at
and drop
1 Symbol Notes
products Flat
delivery
Bars Wire rod forgings
(as products
(see Note 1
blooms,
to Scope)
billets)
Unless
other- as hot None or
a
2 x x x x x –
wise worked +HW
agreed
3 HW + pickled +PI x x x x x
Parti-
cular con-
HW + blast
4 +BC x x x x x
ditions
cleaned
c
supp- –
HW + rough
lied by b
5 +RM – x x – x
machined
agree-
ment
6 others – – x x x x
a
The term “hot worked” also includes the continuously cast condition (+CC) in the case of semi-finished products.
b
Until the term “rough machined” is defined by, for example machining allowances, the details are to be agreed at the time of enquiry and order.
c
In addition, it may be agreed that the products be oiled or, where appropriate, limed or phosphated.
abc
Table 3 — Steel grades and chemical composition (applicable to cast analysis)
Mass fraction
%
Steel name
C Si Mn P S Cr Mo Ni Cu Others
max. max.
Steels without boron
34Cr4 ≤ 0,035
0,30 to 0,10 to 0,60 to
0,025 0,90 to 1,20 – – 0,40 –
d
0,37 0,40 0,90
34CrS4 0,020 to 0,040
37Cr4 ≤ 0,035
0,34 to 0,10 to 0,60 to
0,025 0,90 to 1,20 – – 0,40 –
d
0,41 0,40 0,90
37CrS4 0,020 to 0,040
41Cr4 ≤ 0,035
0,38 to 0,10 to 0,60 to
0,025 0,90 to 1,20 – – 0,40 –
d
0,45 0,40 0,90
41CrS4 0,020 to 0,040
25CrMo4 ≤ 0,035
0,22 to 0,10 to 0,60 to
0,025 0,90 to 1,20 0,15 to 0,30 – 0,40 –
d
0,29 0,40 0,90
25CrMoS4 0,020 to 0,040
34CrMo4 ≤ 0,035
0,30 to 0,10 to 0,60 to
0,025 0,90 to 1,20 0,15 to 0,30 – 0,40 –
d
0,37 0,40 0,90
34CrMoS4 0,020 to 0,040
42CrMo4 ≤ 0,035
0,38 to 0,10 to 0,60 to
0,025 0,90 to 1,20 0,15 to 0,30 – 0,40 –
d
0,45 0,40 0,90
42CrMoS4 0,020 to 0,040
0,46 to 0,10 to 0,50 to
50CrMo4 0,025 ≤ 0,035 0,90 to 1,20 0,15 to 0,30 – 0,40 –
d
0,54 0,40 0,80
41CrNiMo2 ≤ 0,035
0,37 to 0,10 to 0,70 to 0,40 to
0,025 0,40 to 0,60 0,15 to 0,30 0,40 –
d
0,44 0,40 1,00 0,70
41CrNiMoS2 0,020 to 0,040
0,47 to 0,10 to 0,60 to V: 0,10 to 0,25
51CrV4 0,025 ≤ 0,025 0,80 to 1,10 – – 0,40
d
0,55 0,40 1,00 –
0,32 to 0,10 to 0,50 to 0,90 to
36CrNiMo4 0,025 ≤ 0,035 0,90 to 1,20 0,15 to 0,30 0,40 –
d
0,40 0,40 0,80 1,20
0,30 to 0,10 to 0,50 to 1,30 to
34CrNiMo6 0,025 ≤ 0,035 1,30 to 1,70 0,15 to 0,30 0,40 –
d
0,38 0,40 0,80 1,70
0,26 to 0,10 to 0,50 to 1,80 to
30CrNiMo8 0,025 ≤ 0,035 1,80 to 2,20 0,30 to 0,50 0,40 –
d
0,34 0,40 0,80 2,20
10 © ISO 2012 – All rights reserved

Table 3 (continued)
Mass fraction
%
Steel name
C Si Mn P S Cr Mo Ni Cu Others
max. max.
Steels with boron
0,17 to 1,10 to B: 0,0008 to
20MnB5 0,40 0,025 ≤ 0,035 – – – 0,40
0,23 1,40 0,0050
0,27 to 1,15 to B: 0,0008 to
30MnB5 0,40 0,025 ≤ 0,035 – – – 0,40
0,33 1,45 0,0050
0,36 to 1,15 to B: 0,0008 to
39MnB5 0,40 0,025 ≤ 0,035 – – – 0,40
0,42 1,45 0,0050
0,24 to 1,10 to B: 0,0008 to
27MnCrB5-2 0,40 0,025 ≤ 0,035 0,30 to 0,60 – – 0,40
0,30 1,40 0,0050
0,30 to 1,20 to B: 0,0008 to
33MnCrB5-2 0,40 0,025 ≤ 0,035 0,30 to 0,60 – – 0,40
0,36 1,50 0,0050
0,36 to 1,40 to B: 0,0008 to
39MnCrB6-2 0,40 0,025 ≤ 0,035 0,30 to 0,60 – – 0,40
0,42 1,70 0,0050
a
Elements not quoted shall not be intentionally added to the steel without the agreement of the purchaser, other than for the purpose of finishing
the heat. All reasonable precautions should be taken to prevent the addition, from scrap or other material used in manufacture, of such elements, which
affect the hardenability, mechanical properties and applicability.
b
In the case of grades with specified hardenability requirements (see Tables 5 and 6), except for phosphorus and sulfur, insignificant deviations from
the limits for cast analysis are permissible; these deviations shall, however, not exceed in the case of carbon ± 0,01 % and in all other cases, the values
according to Table 4.
c
Steels with improved machinability either by higher sulfur levels up to about 0,10 % S (including controlled sulfide morphology) or lead additions
may be available on request. In the first case, the upper limit of the Mn-content may be increased by 0,15 %.
d
Steels may be supplied with a lower silicon content. In this case, alternative means of deoxidation shall be used.
Table 4 — Permissible deviations between the product analysis and the limiting values given
in Table 3 for the cast analysis
Permissible maximum content according
a
Permissible deviation
to cast analysis
Element
mass fraction
mass fraction
%
%
≤ 0,30 ±0,02
C
0,30 < C ≤ 0,55 ± 0,03
Si ≤ 0,40 ±0,03
≤ 1,00 ±0,04
Mn
1,00 < Mn ≤ 1,70 ± 0,06
P ≤ 0,045 + 0,005
S ≤ 0,045 ±0,005
≤ 2,00 ±0,05
Cr
2,00 < Cr ≤ 2,20 ± 0,10
Cu ≤ 0,40 + 0,05
≤ 0,30 ±0,03
Mo
0,30 < Mo ≤ 0,50 ± 0,04
≤ 1,00 ±0,03
Ni 1,00 < Ni ≤ 2,00 ± 0,05
2,00 < Ni ≤ 2,20 ± 0,07
V ≤ 0,25 ±0,02
B ≤ 0,005 0 ±0,000 3
a
± means that in one cast the deviation may occur over the upper value or under the lower value of the specified range in Table 3,
but not both at the same time.
Table 5 — Hardness limits for steel grades with specified (normal) hardenability (+H grades; see 7.1.4)
Limits of Hardness HRC at a distance, in millimetres, from quenched end of test piece of
Steel name Symbol
range
1,5 3 5 7 9 11 13 15 20 25 30 35 40 45 50
Steels without boron
max. 57 57 56 54 52 49 46 44 39 37 35 34 33 32 31
34Cr4
+H
34CrS4
min. 49 48 45 41 35 32 29 27 23 21 20 - - - -
max. 59 59 58 57 55 52 50 48 42 39 37 36 35 34 33
37Cr4
+H
37CrS4
min. 51 50 48 44 39 36 33 31 26 24 22 20 - - -
max. 61 61 60 59 58 56 54 52 46 42 40 38 37 36 35
41Cr4
+H
41CrS4
min. 53 52 50 47 41 37 34 32 29 26 23 21 - - -
max. 52 52 51 50 48 46 43 41 37 35 33 32 31 31 31
25CrMo4
+H
25CrMoS4
min. 44 43 40 37 34 32 29 27 23 21 20 - - - -
max. 57 57 57 56 55 54 53 52 48 45 43 41 40 40 39
34CrMo4
+H
34CrMoS4
min. 49 49 48 45 42 39 36 34 30 28 27 26 25 24 24
max. 61 61 61 60 60 59 59 58 56 53 51 48 47 46 45
42CrMo4
+H
42CrMoS4
min. 53 53 52 51 49 43 40 37 34 32 31 30 30 29 29
max. 65 65 64 64 63 63 63 62 61 60 58 57 55 54 54
50CrMo4 +H
min. 58 58 57 55 54 53 51 48 45 41 39 38 37 36 36
max. 60 60 60 59 58 57 55 54 48 42 40 38 37 37 36
41CrNiMo2
+H
41CrNiMoS2
min. 53 53 52 50 47 42 38 35 30 28 26 25 24 24 23
max. 65 65 64 64 63 62 62 61 60 58 57 55 54 53 53
51CrV4 +H
min. 57 56 55 54 53 52 50 48 44 41 37 35 34 33 32
max. 59 59 58 58 57 57 57 56 55 54 53 52 51 50 49
36CrNiMo4 +H
min. 51 50 49 49 48 47 46 45 43 41 39 38 36 34 33
max. 58 58 58 58 57 57 57 57 57 57 57 57 57 57 57
34CrNiMo6 +H
min. 50 50 50 50 49 48 48 48 48 47 47 47 46 45 44
max. 56 56 56 56 55 55 55 55 55 54 54 54 54 54 54
30CrNiMo8 +H
min. 48 48 48 48 47 47 47 46 46 45 45 44 44 43 43
Steels with boron
max. 50 49 49 49 47 45 43 41 33 27 - - - - -
20MnB5 +H
min. 42 41 40 37 30 22 - - - - - - - - -
max. 56 55 55 54 53 51 50 47 40 37 33 - - - -
30MnB5 +H
min. 47 46 45 44 42 39 36 31 22 - - - - - -
max. 60 60 59 58 57 57 55 53 48 41 37 33 31 - -
39MnB5 +H
min. 52 51 50 49 47 44 41 35 28 24 20 - - - -
max. 55 55 55 54 54 53 52 51 47 44 40 37 - - -
27MnCrB5-2 +H
min. 47 46 45 44 43 41 39 36 30 24 20 - - - -
max. 57 57 57 57 57 56 55 54 53 50 47 45 - - -
33MnCrB5-2 +H
min. 48 47 47 46 45 44 43 41 36 31 25 20 - - -
max. 59 59 59 59 58 58 58 58 57 57 56 55 54 - -
39MnCrB6-2 +H
min. 51 51 51 51 50 50 50 49 47 45 40 35 32 - -
Table 6 — Hardness limits for steels with narrowed hardenability scatterbands (+HH and +HL grades)
Limits
Hardness HRC at a distance, in millimetres, from quenched end of test piece of
Sym-
Steel name of
bol
1,5 3 5 7 9 11 13 15 20 25 30 35 40 45 50
range
max. 57 57 56 54 52 49 46 44 39 37 35 34 33 32 31
+HH
min. 52 51 49 45 41 38 35 33 28 26 25 24 23 22 21
34Cr4
34CrS4
max. 54 54 52 50 46 43 40 38 34 32 30 29 28 27 26
+HL
min. 49 48 45 41 35 32 29 27 23 21 20 – – – –
12 © ISO 2012 – All rights reserved

Table 6 (continued)
Limits Hardness HRC at a distance, in millimetres, from quenched end of test piece of
Sym-
Steel name of
bol
range 1,5 3 5 7 9 11 13 15 20 25 30 35 40 45 50
max. 59 59 58 57 55 52 50 48 42 39 37 36 35 34 33
+HH
min. 54 53 51 48 44 41 39 37 31 29 27 25 24 23 22
37Cr4
37CrS4
max. 56 56 55 53 50 47 44 42 37 34 32 31 30 29 28
+HL
min. 51 50 48 44 39 36 33 31 26 24 22 20 – – –
max. 61 61 60 59 58 56 54 52 46 42 40 38 37 36 35
+HH
min. 56 55 53 51 47 43 41 39 35 31 29 27 26 25 24
41Cr4
41CrS4
max. 58 58 57 55 52 50 47 45 40 37 34 32 31 30 29
+HL
min. 53 52 50 47 41 37 34 32 29 26 23 21 – – –
max. 52 52 51 50 48 46 43 41 37 35 33 32 31 31 31
+HH
min. 47 46 44 41 39 37 34 32 28 26 24 23 22 22 22
25CrMo4
25CrMoS4
max. 49 49 47 46 43 41 38 36 32 30 29 28 27 27 27
+HL
min. 44 43 40 37 34 32 29 27 23 21 20 – – – –
max. 57 57 57 56 55 54 53 52 48 45 43 41 40 40 39
+HH
min. 52 52 51 49 46 44 42 40 36 34 32 31 30 29 29
34CrMo4
34CrMoS4
max. 54 54 54 52 51 49 47 46 42 39 38 36 35 35 34
+HL
min. 49 49 48 45 42 39 36 34 30 28 27 26 25 24 24
max. 61 61 61 60 60 59 59 58 56 53 51 48 47 46 45
+HH
min. 56 56 55 54 52 48 46 44 41 39 38 36 36 35 34
42CrMo4
42CrMoS4
max. 58 58 58 57 56 54 53 51 49 46 44 42 41 40 40
+HL
min. 53 53 52 51 49 43 40 37 34 32 31 30 30 29 29
max. 65 65 64 64 63 63 63 62 61 60 58 57 55 54 54
+HH
min. 60 60 59 58 57 56 55 53 50 47 45 44 43 42 42
50CrMo4
max. 63 63 62 61 60 60 59 57 56 54 52 51 49 48 48
+HL
min. 58 58 57 55 54 53 51 48 45 41 39 38 37 36 36
max. 60 60 60 59 58 57 55 54 48 42 40 38 37 37 36
+HH
41CrNiMo2
min. 55 55 55 53 51 47 44 41 36 33 31 29 28 28 27
41CrNiMoS2 max. 58 58 57 56 54 52 49 48 42 37 35 34 33 33 32
+HL
min. 53 53 52 50 47 42 38 35 30 28 26 25 24 24 23
max. 65 65 64 64 63 62 62 61 60 58 57 55 54 53 53
+HH
min. 60 59 58 57 56 55 54 52 49 47 44 42 41 40 39
51CrV4
max. 62 62 61 61 60 59 58 57 55 52 50 48 47 46 46
+HL
min. 57 56 55 54 53 52 50 48 44 41 37 35 34 33 32
max. 59 59 58 58 57 57 57 56 55 54 53 52 51 50 49
+HH
min. 54 53 52 52 51 50 50 49 47 45 44 43 41 39 38
36CrNiMo4
max. 56 56 55 55 54 54 53 52 51 50 48 47 46 45 44
+HL
min. 51 50 49 49 48 47 46 45 43 41 39 38 36 34 33
max. 58 58 58 58 57 57 57 57 57 57 57 57 57 57 57
+HH
min. 53 53 53 53 52 51 51 51 51 50 50 50 50 49 48
34CrNiMo6
max. 55 55 55 55 54 54 54 54 54 54 54 54 53 53 53
+HL
min. 50 50 50 50 49 48 48 48 48 47 47 47 46 45 44
max. 56 56 56 56 55 55 55 55 55 54 54 54 54 54 54
+HH
min. 51 51 51 51 50 50 50 49 49 48 48 47 47 47 47
30CrNiMo8
max. 53 53 53 53 52 52 52 52 52 51 51 51 51 50 50
+HL
min. 48 48 48 48 47 47 47 46 46 45 45 44 44 43 43
Table 7 — Maximum hardness for products delivered in the conditions “treated to improve
shearability” (+S) or “soft annealed” (+A)
b
HBW max. in condition
a
Steel name
+S +A
34Cr4, 34CrS4 255 223
37Cr4, 37CrS4 255 235
c
41Cr4, 41CrS4 255 241
25CrMo4, 25CrMoS4 255 212
34CrMo4, 34CrMoS4 255 223
c
42CrMo4, 42CrMoS4 255 241
d
50CrMo4 - 248
41CrNiMo2, 41CrNiMoS2 255 217
d
51CrV4 - 248
d
36CrNiMo4 - 248
d
34CrNiMo6 - 248
d
30CrNiMo8 - 248
e f
20MnB5 - -
e f
30MnB5 - -
e f
39MnB5 - -
e f
27MnCrB5-2 - -
f
33MnCrB5-2 255 -
f
39MnCrB6-2 255 -
a
The values apply also to the
...