EN ISO 3506-5:2023

SLOVENSKI STANDARD
01-januar-2024
Vezni elementi - Mehanske lastnosti veznih elementov iz korozijsko odpornega
nerjavnega jekla - 5. del: Posebni vezni elementi (vključno z veznimi elementi iz
nikljevih zlitin) za uporabo pri visokih temperaturah (ISO 3506-5:2022)
Fasteners - Mechanical properties of corrosion-resistant stainless steel fasteners - Part
5: Special fasteners (also including fasteners from nickel alloys) for high temperature
applications (ISO 3506-5:2022)
Verbindungselemente - Mechanische Eigenschaften von Verbindungselementen aus
nichtrostenden Stählen - Teil 5: Spezielle Verbindungselemente (einschließlich
Verbindungselemente aus Nickellegierungen) für Hochtemperaturanwendungen (ISO
3506-5:2022)
Fixations - Caractéristiques mécaniques des fixations en acier inoxydable résistant à la
corrosion - Partie 5: Fixations spéciales (incluant également les fixations en alliages de
nickel) pour utilisation à hautes températures (ISO 3506-5:2022)
Ta slovenski standard je istoveten z: EN ISO 3506-5:2023
ICS:
21.060.99 Drugi vezni elementi Other fasteners
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 3506-5
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2023
EUROPÄISCHE NORM
ICS 21.060.99
English Version
Fasteners - Mechanical properties of corrosion-resistant
stainless steel fasteners - Part 5: Special fasteners (also
including fasteners from nickel alloys) for high
temperature applications (ISO 3506-5:2022)
Fixations - Caractéristiques mécaniques des fixations Verbindungselemente - Mechanische Eigenschaften
en acier inoxydable résistant à la corrosion - Partie 5: von Verbindungselementen aus nichtrostenden
Fixations spéciales (incluant également les fixations en Stählen - Teil 5: Spezielle Verbindungselemente
alliages de nickel) pour utilisation à hautes (einschließlich Verbindungselemente aus
températures (ISO 3506-5:2022) Nickellegierungen) für Hochtemperaturanwendungen
(ISO 3506-5:2022)
This European Standard was approved by CEN on 29 October 2023.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 3506-5:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO 3506-5:2022 has been prepared by Technical Committee ISO/TC 2 "Fasteners” of the
International Organization for Standardization (ISO) and has been taken over as EN ISO 3506-5:2023 by
Technical Committee CEN/TC 185 “Fasteners” the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2024, and conflicting national standards shall be
withdrawn at the latest by May 2024.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 3506-5:2022 has been approved by CEN as EN ISO 3506-5:2023 without any
modification.
INTERNATIONAL ISO
STANDARD 3506-5
First edition
2022-04
Fasteners — Mechanical properties
of corrosion-resistant stainless steel
fasteners —
Part 5:
Special fasteners (also including
fasteners from nickel alloys) for high
temperature applications
Fixations — Caractéristiques mécaniques des fixations en acier
inoxydable résistant à la corrosion —
Partie 5: Fixations spéciales (incluant également les fixations en
alliages de nickel) pour utilisation à hautes températures
Reference number
ISO 3506-5:2022(E)
ISO 3506-5:2022(E)
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 3506-5:2022(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Symbols . 4
5 Designation system for fasteners made from stainless steels and nickel alloys .5
6 Materials and manufacture .5
6.1 Chemical composition . 5
6.2 Heat treatment for fasteners . . 7
6.3 Finish . 8
6.4 Design of bolt/nut assemblies . 9
6.5 Service temperatures for fasteners . 10
7 Mechanical and physical properties .10
7.1 Mechanical properties of bolts, screws and studs . 10
7.2 Mechanical properties of nuts . 14
8 Applicability of test methods and inspection .15
8.1 Applicability of test methods .15
8.2 Manufacturer’s inspection . 16
8.3 Supplier’s inspection . 16
8.4 Purchaser’s inspection . 16
8.5 Delivery of test results . 16
9 Test methods at ambient temperature.17
9.1 Tensile test for bolts, screws and studs at ambient temperature . 17
9.1.1 General . 17
9.1.2 Applicability . 17
9.1.3 Apparatus and testing device . 17
9.1.4 General test procedure . 18
9.1.5 Test procedure for the simultaneous determination of R , R , and A . 19
mf pf
9.1.6 Reference test procedure for the determination of stress at 0,2 % non-
proportional elongation, R . 20
pf
9.1.7 Alternative test procedure for the determination of elongation, A . 21
9.1.8 Test results and requirements for tensile strength, R .22
mf
9.1.9 Test results and requirements for stress at 0,2 % non-proportional
elongation, R .23
pf
9.1.10 Test results and requirements for elongation after fracture, A .23
9.2 Hardness test for bolts, screws and studs . 23
9.2.1 General .23
9.2.2 Test procedure. 23
9.2.3 Test results and requirements for hardness . 24
9.3 Proof load test for nuts . 24
9.3.1 General . 24
9.3.2 Applicability . 24
9.3.3 Apparatus and testing device . 24
9.3.4 Test procedure.25
9.3.5 Additional testing procedure for prevailing torque nuts . .26
9.3.6 Test results and requirements for nut proof load . 27
9.4 Hardness test for nuts . 27
9.4.1 General . 27
9.4.2 Test procedure. 27
9.4.3 Test results and requirements for nut hardness .28
iii
ISO 3506-5:2022(E)
10 Test methods at high temperature .28
10.1 High temperature tensile test for bolts, screws, studs and nuts .28
10.1.1 General .28
10.1.2 Test apparatus .28
10.1.3 Test procedure.29
10.1.4 Test report .30
10.2 High temperature stress rupture test for bolts, screws, studs and nuts . 31
10.2.1 General . 31
10.2.2 Test apparatus and testing device . 31
10.2.3 Test procedure. 32
10.2.4 Test report . 32
10.3 Relaxation test for bolts, screws, studs and nuts . 33
10.3.1 General . 33
10.3.2 Bolted joint models .33
10.3.3 Test apparatus and measuring devices .34
10.3.4 Test procedure.34
10.3.5 Test results . 35
10.3.6 Test report . 35
10.4 Creep test. 36
11 Fastener marking and labelling .36
11.1 General requirements for marking . 36
11.2 Manufacturer's identification mark . 37
11.3 Marking on the fasteners . 37
11.3.1 Hexagon head bolts and screws and hexagon nuts . 37
11.3.2 Hexagon socket and hexalobular socket bolts and screws .38
11.3.3 Other types of bolts, screws and nuts .38
11.3.4 Studs (one-end and double-end studs) .38
11.3.5 Fully threaded studs .38
11.3.6 Left-hand thread marking . 39
11.4 Marking of the packages (labelling) . 39
Annex A (informative) Tempering of martensitic stainless steels .40
Bibliography .42
iv
ISO 3506-5:2022(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 (see 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 (see 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 of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 2, Fasteners.
A list of all parts in the ISO 3506 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
ISO 3506-5:2022(E)
Introduction
The ISO 3506 series consists of the following parts, under the general title Fasteners — Mechanical
properties of corrosion-resistant stainless steel fasteners:
— Part 1: Bolts, screws and studs with specified grades and property classes
— Part 2: Nuts with specified grades and property classes
1)
— Part 3 : Set screws and similar fasteners not under tensile stress
1)
— Part 4 : Tapping screws
— Part 5: Special fasteners (also including fasteners from nickel alloys) for high temperature applications
— Part 6: General rules for the selection of stainless steels and nickel alloys for fasteners
Complementary detailed explanations about definitions of stainless steel grades and properties are
specified in ISO 3506-6.
The properties of stainless steel and nickel alloy fasteners for high temperature applications result from
the chemical composition of the material, from the heat treatment process and from the manufacturing
process of the fasteners. Static or dynamic properties at room temperature like tensile strength,
hardness or fatigue resistance are not sufficient enough to design fasteners for high temperature
applications properly.
In fact, at high temperatures e.g. above 300 °C, additional phenomena occur, for instance:
— decrease in tensile properties and hardness,
— hot oxidation and scaling,
— stress relaxation,
— creep.
All these phenomena significantly affect the durability and service life of fasteners. Therefore:
— a proper choice of material grade is essential to avoid heavy hot oxidation,
— qualification of fasteners through dedicated tests should be performed.
Different tests are currently available to assess the behaviour of machined and standardized samples
(see for example ASTM E292 or ASTM E328). In addition to these tests, this document specifies test
methods on finished fasteners: these are useful when requiring results as representative as possible of
the actual service conditions.
All fastener categories included in this document are heat-treated (see Clause 6). Heat treatment
processing is crucial to reach mechanical properties and suitable microstructure that are essential to
stand phenomena described above and to get adequate durability for the fasteners and the assembled
bolted joints.
1) It is intended to revise ISO 3506-3 and ISO 3506-4 in the future in order to include the reference to ISO 3506-6.
vi
INTERNATIONAL STANDARD ISO 3506-5:2022(E)
Fasteners — Mechanical properties of corrosion-resistant
stainless steel fasteners —
Part 5:
Special fasteners (also including fasteners from nickel
alloys) for high temperature applications
1 Scope
This document specifies the mechanical and physical properties of bolts, screws, studs and nuts, with
coarse pitch thread and fine pitch thread, made of corrosion-resistant stainless steels (i.e. martensitic
stainless steels and precipitation hardening austenitic stainless steels) and nickel alloys, intended for
use at high temperatures up to 800 °C.
Tests in accordance with Clause 9 are performed at the ambient temperature range of 10 °C to 35 °C,
and other tests can be performed at higher temperatures, see Clause 10.
NOTE Fasteners specified in this document are also suitable when used at low temperatures, typically down
to -50 °C. For more information, see ISO 3506-6.
The term “fasteners” is used in this document when bolts, screws, studs and nuts are considered all
together.
ISO 3506-6 provides general rules and additional technical information on suitable stainless steels and
nickel alloys as well as their properties.
This document applies to fasteners:
— with ISO metric thread in accordance with ISO 68-1,
— with diameter/pitch combinations in accordance with ISO 261 and ISO 262,
— with coarse pitch thread M3 to M39, and fine pitch thread M8×1 to M39×3,
— with thread tolerances in accordance with ISO 965-1 and ISO 965-2, and
— of any shape but with full loadability.
Stainless steel and nickel alloy fastener symbols can be used for sizes outside the diameter limits of this
document (i.e. for bolts, screws and studs with d < 3 mm or d > 39 mm and for nuts with D < 5 mm or
D > 39 mm), provided that all applicable chemical, mechanical and physical requirements are met.
Fasteners with reduced loadability (i.e. thin nuts and bolts, screws and studs with head or unthreaded
shank weaker than the threaded shank) are not dealt with in this document.
This document does not specify requirements for functional properties such as:
— torque/clamp force properties,
— shear strength,
— fatigue resistance,
— weldability,
ISO 3506-5:2022(E)
or
— properties of bolted joints and fasteners in high temperature environment (see test methods at high
temperature for fasteners in Clause 10).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 1891-4, Fasteners — Vocabulary — Part 4: Control, inspection, delivery, acceptance and quality
ISO 3506-1, Fasteners — Mechanical properties of corrosion-resistant stainless steel fasteners — Part 1:
Bolts, screws and studs with specified grades and property classes
ISO 3506-2, Fasteners — Mechanical properties of corrosion-resistant stainless steel fasteners — Part 2:
Nuts with specified grades and property classes
ISO 3506-6, Fasteners — Mechanical properties of corrosion-resistant stainless steel fasteners — Part 6:
General rules for the selection of stainless steels and nickel alloys for fasteners
ISO 6506-1, Metallic materials — Brinell hardness test — Part 1: Test method
ISO 6507-1, Metallic materials — Vickers hardness test — Part 1: Test method
ISO 6508-1, Metallic materials — Rockwell hardness test — Part 1: Test method
ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
ISO 7500-1, Metallic materials — Calibration and verification of static uniaxial testing machines — Part 1:
Tension/compression testing machines — Calibration and verification of the force-measuring system
ISO 9513, Metallic materials — Calibration of extensometer systems used in uniaxial testing
ISO 16228, Fasteners — Types of inspection documents
EN 10319-2, Metallic materials — Tensile stress relaxation testing — Part 2: Procedure for bolted joint
models
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
stainless steel
steel with at least 10,5 % (mass fraction) of chromium (Cr) and maximum 1,2 % (mass fraction) of
carbon (C)
[SOURCE: ISO 3506-1:2020, 3.5]
ISO 3506-5:2022(E)
3.2
martensitic stainless steel
stainless steel (3.1) with high amounts of chromium but very little nickel or other alloying elements,
which can be hardened by heat treatment for increasing strength but with reduced ductility, and with
highly magnetic properties
[SOURCE: ISO 3506-1:2020, 3.7]
3.3
precipitation hardening austenitic stainless steel
austenitic stainless steel that can be hardened through precipitation of intermetallic phases from its
supersaturated metallic matrix
3.4
nickel alloy
alloy whose main constituent is nickel
3.5
soaking time
time that the entire part being heat-treated (throughout its cross-sections) remains at the specified set
temperature
3.6
stainless steel bolt and screw with full loadability
nickel alloy bolt and screw with full loadability
bolt and screw with head stronger than the threaded and unthreaded shanks (with unthreaded shank
diameter d ≈ d or d > d ) or screw threaded to the head, and fulfilling the minimum ultimate tensile
s 2 s 2
load
[SOURCE: ISO 3506-1:2020, 3.1 modified]
3.7
stainless steel stud with full loadability
nickel alloy stud with full loadability
stud with unthreaded shank diameter d ≈ d or d > d , and fulfilling the minimum ultimate tensile load
s 2 s 2
[SOURCE: ISO 3506-1:2020, 3.2 modified]
3.8
stainless steel nut with full loadability
nickel alloy nut with full loadability
regular nut or high nut fulfilling the requirements for proof load and with minimum height m ≥ 0,80D
min
or m ≥ 0,73D
th,design,min
Note 1 to entry: The limits for the minimum height m ≥ 0,80D (for standard nuts) or m ≥ 0,73D (for
min th,design,min
other nuts) are explained in 6.4.
3.9
resistance to high temperature environment
extent to which a fastener retains required functional properties (e.g. resistance against oxidation,
relaxation, creep) during exposure to a specified temperature for a specified duration and/or to
temperature cycles
3.10
creep
time-dependent strain that occurs after the application of a force which is thereafter maintained
constant
3.11
relaxation
time-dependent stress loss for a constant strain
ISO 3506-5:2022(E)
4 Symbols
For the purposes of this document, the following symbols apply.
A Total elongation after fracture for full-size fastener, mm
A Total elongation after fracture for full-size fastener at high temperature, mm
T
A Nominal stress area in thread, mm
s,nom
b Thread length, mm
d, D Nominal thread diameter, mm
d Basic minor diameter of external thread, mm
d Basic pitch diameter of external thread, mm
D Basic pitch diameter of internal thread, mm
d Minor diameter of external thread (for nominal stress area calculation), mm
d Hole diameter of the grip in tensile testing device, mm
h
d Diameter of unthreaded shank, mm
s
F Ultimate tensile load for full-size fastener, N
mf
F Ultimate tensile load for full-size fastener at high temperature, N
mf,T
F Ultimate stripping load at high temperature for the nut, N
n,T
F Proof load for nut, N
P
F Load at 0,2 % non-proportional elongation for full-size fastener, N
pf
F Load at 0,2 % non-proportional elongation for full-size fastener at high temperature, N
pf,T
h Thickness of the nut grip in tensile testing device, mm
H Height of the fundamental triangle of the thread, mm
l Nominal length of fastener, mm
L Total length of fastener before tensile test, mm
L Total length of fastener after fracture, mm
L Clamping length before tensile test, mm
l Overall length of stud, mm
t
l Free threaded length of fastener in testing device, mm
th
m Height of the nut, mm
m Design thread height of the nut, mm
th,design
P Pitch of the thread, mm
R Tensile strength for full-size fastener, MPa
mf
ISO 3506-5:2022(E)
R Tensile strength for full-size fastener at high temperature, MPa
mf,T
R Ultimate nut strength at stripping load at high temperature, MPa
n,T
R Stress at 0,2 % non-proportional elongation for full-size fastener, MPa
pf
R Stress at 0,2 % non-proportional elongation for full-size fastener at high temperature, MPa
pf,T
S Stress under proof load for nuts, MPa
P
5 Designation system for fasteners made from stainless steels and nickel alloys
All stainless steels and nickel alloys specified in this document belong to one of the three following
categories:
— martensitic stainless steels (3.2): CH0, CH1, CH2, V, VH, and VW,
— precipitation hardening austenitic stainless steels (3.3): SD,
— nickel alloys (3.4): SB and 718.
The chemical composition and heat treatment of fasteners for these three material categories are
specified in Clause 6.
The marking, labelling and designation with the fastener symbols of Clause 6 shall be as specified in
Clause 11.
6 Materials and manufacture
6.1 Chemical composition
Tables 1 to 3 specify the limits for chemical composition of the stainless steels and nickel alloys for
fasteners. The chemical composition shall be assessed in accordance with the relevant International
Standards.
The final choice of the chemical composition within the specified fastener symbol is at the discretion of
the manufacturer, unless otherwise agreed between the purchaser and the manufacturer.
The stainless steel or nickel alloy grade suitable for an application shall be selected in accordance with
the specifications defined in ISO 3506-6 (see also Bibliography for additional material information).
ISO 3506-5:2022(E)
Table 1 — Chemical composition for martensitic stainless steel fasteners
Chemical composition
Mass fraction, %
Fastener Material
(maximum values unless stated otherwise)
symbol reference
Other
C Si Mn P S Cr Mo Ni N
elements
a
4021-420-00-I
0,16 to 0,030 12,0
CH0 1,00 1,50 0,040 — — — —
c
b
0,25 to 14,0
1.4021
a
4028-420-00-I 0,26
0,030 12,0
CH1 to 1,00 1,50 0,040 — — — —
c
b to 14,0
1.4028
0,35
a
4057-431-00-X 1,50
0,12 to 0,030 15,0
CH2 1,00 1,50 0,040 — to — —
c
b
0,22 to 17,0
1.4057
2,50
a
4923-422-77-E 0,80 0,30
0,18 to 0,40 11,0 to
d
V or VH 0,50 0,025 0,015 to to — V: 0,25 to 0,35
e
0,24 to 0,90 12,5
1.4923
1,20 0,80
V: 0,10 to 0,30
0,50 0,20
0,17 to 0,40 10,0 to 0,05 Nb: 0,25 to 0,55
e
VW 1.4913 0,50 0,025 0,015 to to
0,23 to 0,90 11,5 to 0,10 B ≤ 0,0015
0,80 0,60
Al ≤ 0,020
a
Material reference given for information according to ISO 15510.
b
Material reference given for information according to EN 10088-3.
c
For machinability, a controlled sulfur mass fraction of 0,015 % to 0,030 % is recommended.
d
Symbol V for stress at 0,2 % non-proportional elongation R ≥ 600 MPa, and symbol VH for R ≥ 700 MPa, in accordance
pf pf
with Table 7.
e
Material reference given for information according to EN 10269.
Table 2 — Chemical composition for precipitation hardening austenitic stainless steel fasteners
Chemical composition
Mass fraction, %
Fastener Material
(maximum values unless stated otherwise)
symbol reference
Other
C Si Mn P S Cr Mo Ni Ti
elements
b
4980-662-86-X Al ≤ 0,35
1,00
0,080 13,5 24,0 1,90 to V: 0,10 to 0,50
1,00 2,00 0,040 0,030 to
Alloy 660
e
to 16,0 to 27,0 2,35 B: 0,0010 to
c
1,50
UNS S66286
0,010
a
SD
Al ≤ 0,35
0,030 1,00 1,00
13,5 24,0 1,90 to V: 0,10 to 0,50
d
1.4980 to 1,00 to 0,025 0,015 to
to 16,0 to 27,0 2,30 B: 0,0030 to
0,080 2,00 1,50
0,010
a
Secondary melting (for instance Electro-Slag Remelting) of the raw material is recommended due to the beneficial
effect on the functional properties of the finished fasteners. The melting process is left to the choice of the fastener
manufacturer, unless otherwise agreed.
b
Material reference given for information according to ISO 15510.
c
Material reference given for information according to ASTM A453/A453M.
d
Material reference given for information according to EN 10269.
e
A minimum carbon content may be required for specific applications.
ISO 3506-5:2022(E)
Table 3 — Chemical composition for nickel alloy fasteners
Chemical composition
Mass fraction, %
Fastener Material
(maximum values unless stated otherwise)
symbol reference
Other
C Si Mn P S Cr Mo Ni Ti
elements
Alloy 80A 18,0 Re- 1,80 Al: 0,50 to 1,80
c
0,10 1,00 1,00 — 0,015 —
b
UNS N07080 to 21,0 minder to 2,70 Fe ≤ 3,00
Al: 1,00 to 1,80
SB
Fe ≤ 1,50
a
0,040 18,0 1,80
d
2.4952 1,00 1,00 0,020 0,015 — ≥ 65 Co ≤ 1,00
to 0,10 to 21,0 to 2,70
Cu ≤ 0,20
B ≤ 0,0080
Nb + Ta: 4,75 to
5,50
2,80
Alloy 718 0,080 17,0 to 0,65 Al: 0,20 to 0,80
0,35 0,35 0,015 0,015 to 50 to 55
e c
UNS N07718 21,0 to 1,15 Co ≤ 1,00
3,30
Cu ≤ 0,30
B ≤ 0,0060
Nb + Ta: 4,7 to
a
5,5
0,020 2,80 0,60 Al: 0,30 to 0,70
17,0 to
f
2.4668 to 0,35 0,35 0,015 0,015 to 50 to 55 to Co ≤ 1,00
21,0
0,080 3,30 1,20 Cu ≤ 0,30
B ≤ 0,0020 to
0,0060
a
Secondary melting (for instance Electro-Slag Remelting) of the raw material is recommended due to the beneficial
effect on the functional properties of the finished fasteners. The melting process is left to the choice of the fastener
manufacturer, unless otherwise agreed.
b
Material references given for information according to ASTM B637.
c
A minimum carbon content may be required for specific applications.
d
Material references given for information according to EN 10269.
e
Material references given for information according to ASTM A1014.
f
Material references given for information according to EN 10302.
6.2 Heat treatment for fasteners
Fasteners shall be heat treated in order to meet the mechanical and physical properties specified in
Clause 7.
Heat treatment requirements are specified in Table 4. The minimum tempering temperature for
martensitic stainless steels shall be selected in accordance with Table 4, by taking into account the
mechanical and physical properties required in Table 7 as well as the temperature at which the
fasteners are intended to be used.
The process steps shall be as follows:
— for SD, SB and 718, solution annealing (AT) shall be carried out. In addition, it is strongly recommended
to perform AT after the manufacture of the fasteners; however, for externally threaded fasteners
with tensile strength R above or equal to 1 100 MPa, AT could be performed on the raw material
mf
(before manufacturing the fasteners) subject to prior agreement between the purchaser and the
manufacturer at the time of order;
— for cold and hot forged fasteners, heat treatment shall be performed after the manufacture of the
fasteners;
ISO 3506-5:2022(E)
— for fasteners machined from bars, heat treatment can be carried out on the raw material or after the
manufacture of the fasteners.
For externally threaded fasteners, thread rolling can be carried out before or after heat treatment, or
between solution annealing (AT) and precipitation hardening (P) steps.
Table 4 — Heat treatment for fasteners
Temperature range for
Temperature for tempering/
quenching/solution
Fastener Heat treatment precipitation hardening
annealing
symbol condition °C
°C
[and soaking time (3.5)]
[and soaking time (3.5)]
a, b
CH0 +QT 950 to 1 050 ≥ 450
a, b
CH1 +QT 950 to 1 050 ≥ 450
a, b
CH2 +QT 950 to 1 050 ≥ 450
a
V +QT 1 020 to 1 070 ≥ 550
a
VH +QT 1 020 to 1 070 ≥ 550
a
VW +QT 1 100 to 1 130 ≥ 550
970 to 990 [≥ 1 h]
704 to 760
SD +AT+P
[≥ 16 h]
890 to 910 [≥ 1 h]
st
1 step: 840 to 860 [≥ 24h]
SB +AT+P 1 050 to 1 080
nd
2 step: 690 to 710 [≥ 16h]
st
1 step: 710 to 730 [≥ 8 h]
nd
2 step: 610 to 630
718 +AT+P 940 to 1 010
Total treatment time:
18 h minimum
QT Quenched and Tempered.
AT Solution annealed (Annealing Treatment).
P Precipitation hardened.
a
When the intended service temperature is specified by the customer, the manufacturer shall choose
a tempering temperature above this service temperature and in accordance with this Table 4. Otherwise,
the tempering temperature is left to the choice of the manufacturer providing that the required mechanical
and physical properties of the fasteners are met.
b
Tempering temperature between 500 °C and 600 °C should be avoided (loss of toughness and increased
risk of intergranular corrosion): see information in Annex A.
Soaking times which are not specified in Table 4 are left to the choice of the manufacturer. Cooling
media are not specified in Table 4, they are left to the choice of the manufacturer (see e.g. EN 10269).
6.3 Finish
Unless otherwise specified, fasteners shall be supplied clean.
Fasteners are often used in bolted joints where the preload is applied by torque tightening. Lubrication
of stainless steel and nickel alloy fasteners is recommended in order to avoid galling during tightening.
NOTE 1 Several parameters can increase the risk of galling for stainless steel and nickel alloy fasteners in
bolted assemblies during tightening such as thread damage, high preload,
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