ISO 683-4:2014
(Main)Heat-treatable steels, alloy steels and free-cutting steels — Part 4: Free-cutting steels
Heat-treatable steels, alloy steels and free-cutting steels — Part 4: Free-cutting steels
ISO 683-4:2014 gives the technical delivery requirements for semi-finished products (e.g. blooms, billets, slabs), bars, and wire rod, manufactured from free-cutting steels listed and supplied in one of the treatment conditions given for the different types of products. It covers three groups of free-cutting steels for mechanical purposes: not intended for heat treatment, suitable for case-hardening, and suitable for quenching and tempering.
Aciers pour traitement thermique, aciers alliés et aciers pour décolletage — Partie 4: Aciers pour décolletage
General Information
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 683-4
First edition
2014-08-01
Heat-treatable steels, alloy steels and
free-cutting steels —
Part 4:
Free-cutting steels
Aciers pour traitement thermique, aciers alliés et aciers pour
décolletage —
Partie 4: Aciers pour décolletage
Reference number
ISO 683-4:2014(E)
©
ISO 2014
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ISO 683-4:2014(E)
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ISO 683-4:2014(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Classification and designation . 2
4.1 Classification . 2
4.2 Designation . 2
5 Information to be supplied by the purchaser. 2
5.1 Mandatory information . 2
5.2 Options/Supplementary or special requirements . 3
6 Manufacturing process . 3
6.1 General . 3
6.2 Heat treatment and surface condition at delivery . 3
6.3 Traceability of the cast . 3
7 Requirements . 4
7.1 Chemical composition, hardness, and mechanical properties . 4
7.2 Machinability . 4
7.3 Weldability . 4
7.4 Grain size . 4
7.5 Internal soundness . 4
7.6 Surface quality . 5
7.7 Shape, dimensions, and tolerances . 5
8 Inspection . 5
8.1 Testing procedures and types of documents . 5
8.2 Frequency of testing . 6
8.3 Specific inspection and testing . 6
9 Test methods . 6
9.1 Chemical analysis . 6
9.2 Hardness and mechanical tests . 6
9.3 Retests . 6
10 Marking . 7
Annex A (normative) Ruling sections for mechanical properties .14
Annex B (normative) Supplementary or special requirements .17
Annex C (informative) Designation of steels given in this part of ISO 683 and of comparable grades
covered in various designation systems .19
Annex D (informative) Dimensional standards applicable to products complying with this part of
ISO 683 .20
Bibliography .21
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ISO 683-4:2014(E)
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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directives
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. Details of any
patent rights identified during the development of the document will be in the Introduction and/or on
the ISO list of patent declarations received. www.iso.org/patents
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 17, Steel, Subcommittee SC 4, Heat treatable and
alloy steels.
This first edition cancels and replaces ISO 683-9:1988, which has 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 3: Case hardening steels
— Part 4: Free-cutting steels
— Part 5: Nitriding 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 steel products
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INTERNATIONAL STANDARD ISO 683-4:2014(E)
Heat-treatable steels, alloy steels and free-cutting steels —
Part 4:
Free-cutting steels
1 Scope
This part of ISO 683 gives the technical delivery requirements for semi-finished products (e.g. blooms,
billets, slabs), bars, and wire rod, manufactured from the free-cutting steels listed in Table 2 and supplied
in one of the treatment conditions given for the different types of products in Table 1, rows 2 to 4.
This part of ISO 683 covers three groups of free-cutting steels for mechanical purposes as listed in
Table 2, namely
a) not intended for heat treatment,
b) suitable for case-hardening, and
c) suitable for quenching and tempering.
Free-cutting steels are often used as bright bars. For these products please refer to ISO 683-18.
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).
In addition to this part of ISO 683, the general technical delivery requirements of ISO 404 are applicable.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
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 643, Steels — Micrographic determination of the apparent grain size
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 6506-1, Metallic materials — Brinell hardness test — Part 1: Test method
ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
ISO 6929, Steel products — Vocabulary
ISO 9443, Heat-treatable and alloy steels — Surface quality classes for hot-rolled round bars and wire
rods — Technical delivery conditions
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ISO 683-4:2014(E)
ISO 10474, Steel and steel products — Inspection documents
ISO 14284, Steel and iron — Sampling and preparation of samples for the determination of chemical
composition
ISO/TR 9769, Steel and iron — Review of available methods of analysis
ISO/TS 4949, Steel names based on letter symbols
3 Terms and definitions
For the purposes of this document, the definitions given in ISO 377, ISO 4885, ISO 4948-1, ISO 4948-2,
ISO 6929, and ISO 14284, and the following apply.
3.1
ruling section
section for which the specified mechanical properties shall apply
Note 1 to entry: 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, show the same cooling rate as the actual ruling
section of the product concerned at its position for taking the test pieces.
3.2
free-cutting steels
steels characterized by good machinability, i.e. high metal removal rate, mostly obtained by higher than
normal contents of sulfur
Note 1 to entry: Other elements besides sulfur can be added for further improving the machinability.
4 Classification and designation
4.1 Classification
The classification of the relevant steel grades is allocated in accordance with ISO 4948-1 and ISO 4948-2.
All steels covered by this part of ISO 683 are classified as non-alloy quality steels.
4.2 Designation
For the steel grades covered by this part of ISO 683, the steel names 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 (e.g. slab, bloom, billet, round bar, wire rod);
c) either the designation of the dimensional standard and the dimensions and tolerances selected from
this (see 7.7) or the designation of the drawing or any other document, covering the dimensions and
tolerances required for the product;
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ISO 683-4:2014(E)
d) a reference to this part of ISO 683 (i.e. ISO 683-4);
e) the designation of the steel grade given in Table 2;
f) standard designation for a test report 2.2 or, if required, any other type of inspection document in
accordance with ISO 10474.
5.2 Options/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 specification of this part of ISO 683 (see 5.1).
a) if a heat-treatment condition other than the untreated condition is required, the symbol for this
other condition (see Table 1, column 2)
b) any supplementary requirement that shall comply with the symbol and, where necessary, the details
of this supplementary requirement (see Annex B)
c) suitability of bars and rod for bright drawing (see 7.6.4)
d) any requirement relating to removal of surface defects (see 7.6.5)
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 683-4, 35S20 (see Table 2) in the heat-treatment condition +U (see Table 1),
product analysis/option B.5 with a test report 2.2 in accordance with ISO 10474.
50 round bars ISO 1035 – 40,0S x 8 000L2
steel grade ISO 683-4 – 35S20 option B.5
Inspection document ISO 10474 – 2.2
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 and 6.3, left to the discretion of the manufacturer.
For minimum reduction ratio or minimum thickness deformation ratio of rolled and forged products,
see B.6.
6.2 Heat treatment and surface condition at delivery
6.2.1 Normal condition at delivery
Unless otherwise agreed at the time of enquiry and order, the products shall be delivered in the untreated
condition that means “as hot-worked”.
6.2.2 Particular heat-treatment condition
If so agreed at the time of enquiry and order, the products shall be delivered in one of the particular heat-
treatment conditions given in Table 1, rows 3 and 4.
6.3 Traceability of the cast
Each product shall be traceable to the cast (see Clause 10).
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ISO 683-4:2014(E)
7 Requirements
7.1 Chemical composition, hardness, and mechanical properties
7.1.1 General
Table 1 gives a survey of combinations of usual treatment conditions at delivery, product forms, and
requirements according to Tables 2 to 6 (chemical composition, maximum hardness, mechanical
properties).
7.1.2 Chemical composition
The chemical composition determined by cast analysis shall comply with the values in Table 2.
Permissible deviations between the limiting values for cast analysis and the values for product analysis
are given in Table 3.
The product analysis shall be carried out when specified at the time of the enquiry and order (see B.5).
WARNING — Due to hazardous effects to health and environmental problems of Pb, it is
recommended to instead use steels only with sulfur and other innocuous free-cutting element
additions.
7.1.3 Mechanical properties
Mechanical properties for free-cutting steels are given in Tables 4 to 6.
7.2 Machinability
The steels covered by this part of ISO 683 have good machinability and chip-breaking characteristics.
However, the machinability decreases with increasing carbon, silicon, and manganese contents, while
cold reduction improves the machinability of the steels not intended for heat treatment and steel 10S20.
NOTE Non-leaded steels with comparable chemical composition generally have identical mechanical
properties, but often lower machinability than leaded steels.
7.3 Weldability
Because of their high sulfur and phosphorus content, free-cutting steels are normally not recommended
for welding.
7.4 Grain size
Unless otherwise agreed at the time of enquiry and order, the grain size shall be left to the discretion of
the manufacturer. If a fine grain structure is required for case-hardening steels or steels for quenching
and tempering, the special requirement in B.3 shall be ordered.
If direct hardening treatment is used for case-hardening steels, a fine grain structure should be ordered.
7.5 Internal soundness
Where appropriate, requirements relating to the internal soundness of the products shall be agreed at
the time of enquiry and order (seeB.4).
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ISO 683-4:2014(E)
7.6 Surface quality
7.6.1 All products shall have a smooth surface finish appropriate to the manufacturing processes
applied.
7.6.2 Minor surface imperfections, which can occur under normal manufacturing conditions, such as
prints originating from rolled-in scale, are not to be regarded as defects.
7.6.3 Bars and wire rod are delivered with surface class A according to ISO 9443, unless otherwise
agreed at the time of enquiry and order.
NOTE It is more difficult to detect and eliminate surface discontinuities in coiled products than in cut lengths.
This should be taken into account when agreements on surface quality are made.
7.6.4 If suitability of bars and rod for bright drawing is required, this shall be agreed at the time of
enquiry and order.
7.6.5 The removal of surface defects by welding is not permitted.
If surface discontinuities are repaired, the method and maximum depth of removal shall be agreed at
the time of enquiry and order.
7.7 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 much as possible, be based on corresponding
International Standards (see Annex D), or 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 specified in ISO 10474. 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 of the concerned cast for all elements specified in Table 2 for the steel
grade.
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 8.2, 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 the following:
a) confirmation that the material complies with the requirements of the order;
b) results of the cast analysis of the concerned cast for all elements specified in Table 2 for the steel
grade;
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ISO 683-4:2014(E)
c) the result 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
compliance with the requirements shall be in accordance with the prescriptions of Table 7.
8.3 Specific inspection and testing
8.3.1 Verification of the hardness and mechanical properties
The hardness requirements and/or mechanical properties given for the relevant treatment condition
in Table 1, column 6, sub-column 6.2, shall be verified, with the following exception. The requirements
given in footnote a to Table 1 (mechanical properties of reference test pieces), shall only be verified if the
supplementary requirement given in B.2, is ordered.
8.3.2 Visual and dimensional inspection
A sufficient number of products shall be inspected to ensure 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.
The list of available International Standards on chemical analysis is given in ISO/TR 9769.
9.2 Hardness and mechanical tests
9.2.1 Hardness
For products in the untreated condition, the hardness shall be measured in accordance with ISO 6506-1.
9.2.2 Mechanical tests
The tensile test shall be carried out in accordance with ISO 6892-1.
For the specified yield strength in the tables of 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
9.3 Retests
Retests for steels for quenching and tempering and criteria should be as specified in ISO 404.
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ISO 683-4:2014(E)
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 name, and the origin of the delivery is possible
(see B.7).
Table 1 — Combinations of usual heat-treatment conditions at delivery, product forms, and
requirements according to Tables 2 to 6
1 2 3 4 5 6
1 Heat- Symbol x = applicable for Applicable requirements
treatment
Semi- Bars Wire rod 6.1 6.2
condition at
finished
delivery
products
2 Untreated None or x x x Chemical compo- Maximum Brinell hardness or (in the case
+U sition according of dispute) the tensile strength according
to Tables 2 and 3 to Table 4 in the case of steels not intended
for heat treatment or Table 5 in the case of
case-hardening steels or Table 6 in the case of
a
steels for quenching and tempering
3 Quenched +QT — x — Mechanical properties according to Table 6 in
and tem- the case of steels for quenching and temper-
pered ing
4 Others Other treatment conditions, for example the stress relieved condition, can be agreed at the time of enquiry and
order.
a
The mechanical properties specified in Table 6 for the quenched + tempered condition shall be achievable after
appropriate heat treatment if so agreed at the time of enquiry and order (see B.2).
Table 2 — Steel grades and chemical composition (cast analysis)
a
% mass fraction
Steel name
C Si Mn P S Pb
Steels not intended for heat treatment
b c
9S20 0,13 0,05 0,60 to 1,20 0,11d 0,15 to 0,25 —
11SMn30 —
b c
0,14 0,05 0,90 to 1,30 0,11 0,27 to 0,33
11SMnPb30 0,20 to 0,35
11SMn37 —
b c
0,14 0,05 1,00 to 1,50 0,11 0,34 to 0,40
11SMnPb37 0,20 to 0,35
Case-hardening steels
10S20 —
0,07 to 0,13 0,40 0,70 to 1,10 0,060 0,15 to 0,25
10SPb20 0,20 to 0,35
15SMn13 0,12 to 0,18 0,40 0,90 to 1,30 0,060 0,08 to 0,18 —
17SMn20 0,14 to 0,20 0,40 1,20 to 1,60 0,060 0,15 to 0,25 —
Steels for quenching and tempering
35S20 —
0,32 to 0,39 0,40 0,70 to 1,10 0,060 0,15 to 0,25
35SPb20 0,15 to 0,35
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 shall be taken to prevent the addition of such elements from scrap
or other materials used in manufacture which affect the mechanical properties and applicability. However, if agreed, the
manufacturer can add elements such as Ca, Se, Te, etc. for the purpose of improving the machinability. These elements have
to be reported in the inspection document.
a
Maximum values unless otherwise indicated.
b
Since silicon has an adverse effect on machinability, it is not intentionally added to specified limits, but if the formation
of special oxides is guaranteed, a Si-content of 0,10 to 0,40 % can be agreed.
c
At the time of enquiry and order, it can be agreed that either a grade with 0,06 to 0,11 % P or a grade with max. 0,05 % P
shall be delivered.
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ISO 683-4:2014(E)
Table 2 (continued)
a
% mass fraction
Steel name
C Si Mn P S Pb
36SMn14 —
0,32 to 0,39 0,40 1,30 to 1,70 0,060 0,10 to 0,18
36SMnPb14 0,15 to 0,35
35SMn20 —
0,32 to 0,39 0,40 0,90 to 1,40 0,060 0,15 to 0,25
35SMnPb20 0,15 to 0,35
38SMn28 —
0,35 to 0,40 0,40 1,20 to 1,50 0,060 0,24 to 0,33
38SMnPb28 0,15 to 0,35
44SMn28 —
0,40 to 0,48 0,40 1,30 to 1,70 0,060 0,24 to 0,33
44SMnPb28 0,15 to 0,35
46S20 —
0,42 to 0,50 0,40 0,70 to 1,10 0,060 0,15 to 0,25
46SPb20 0,15 to 0,35
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 shall be taken to prevent the addition of such elements from scrap
or other materials used in manufacture which affect the mechanical properties and applicability. However, if agreed, the
manufacturer can add elements such as Ca, Se, Te, etc. for the purpose of improving the machinability. These elements have
to be reported in the inspection document.
a
Maximum values unless otherwise indicated.
b
Since silicon has an adverse effect on machinability, it is not intentionally added to specified limits, but if the formation
of special oxides is guaranteed, a Si-content of 0,10 to 0,40 % can be agreed.
c
...
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