SIST EN ISO 898-2:2012

Mechanical properties of fasteners made of carbon steel and alloy steel - Part 2: Nuts with specified property classes - Coarse thread and fine pitch thread (ISO 898-2:2012)

This part of ISO 898 specifies mechanical and physical properties of nuts with coarse thread and fine pitch
thread made of carbon steel and alloy steel when tested at an ambient temperature range of 10 °C to 35 °C.
Nuts conforming to the requirements of this part of ISO 898 are evaluated at that ambient temperature range.
It is possible that they do not retain the specified mechanical and physical properties at elevated and/or lower
temperatures.
NOTE 1 Nuts conforming to the requirements of this part of ISO 898 have been used in applications
ranging from ?50 °C to +150 °C. It is the responsibility of users to consult an experienced fastener materials expert
for temperatures outside the range of ?50 °C to +150 °C and up to a maximum temperature of +300°C to determine
appropriate choices for a given application.
NOTE 2 Information for the selection and application of steels for use at lower and elevated temperatures is given for
instance in EN 10269, ASTM F2281 and in ASTM A320/A320M.
This part of ISO 898 is applicable to nuts:
a) made of carbon steel or alloy steel;
b) with coarse thread M5 ≤ D ≤ M39, and fine pitch thread M8×1 ≤ D ≤ M39×3;
c) with triangular ISO metric thread according to ISO 68-1;
d) with diameter/pitch combinations according to ISO 261 and ISO 262;
e) with specified property classes, including proof load;
f) with different nut styles: thin nuts, regular nuts and high nuts;
g) with minimum height m ≥ 0,45D;
h) with a minimum outside diameter or width across flats s ≥ 1,45D (see Annex A);
i) able to mate with bolts, screws and studs with property classes according to ISO 898-1.
For hot dip galvanized nuts, see ISO 10684.
This part of ISO 898 does not specify requirements for properties such as:
— prevailing torque properties (see ISO 2320);
— torque/clamp force properties (see ISO 16047 for test method);
— weldability;
— corrosion resistance.

Mechanische Eigenschaften von Verbindungselementen aus Kohlenstoffstahl und legiertem Stahl - Teil 2: Muttern mit festgelegten Festigkeitsklassen - Regelgewinde und Feingewinde (ISO 898-2:2012)

Dieser Teil von ISO 898 legt mechanische und physikalische Eigenschaften von Muttern aus Kohlenstoffstahl
und legiertem Stahl mit Regelgewinde fest, die in einem Bereich der Umgebungstemperatur von 10 °C bis
35 °C geprüft werden.
Muttern, die den Anforderungen dieser Norm entsprechen, werden in diesem Bereich der
Umgebungstemperatur bewertet. Es kann sein, dass sie die festgelegten mechanischen und physikalischen
Eigenschaften bei höheren Temperaturen und/oder niedrigeren Temperaturen nicht beibehalten.
ANMERKUNG 1 Muttern, die den Anforderungen dieser Norm entsprechen, werden für Anwendungen im Bereich von
−50 °C bis +150 °C eingesetzt. Anwender sollten für Temperaturen außerhalb des Bereiches von −50 °C und +150 °C
sowie bis zu einer Höchsttemperatur von +300 °C einen erfahrenen Metallurgen für Verbindungselemente konsultieren,
um die geeignete Wahl für die vorgesehene Anwendung zu treffen.
ANMERKUNG 2 Informationen zur Auswahl und Anwendung von Stählen für den Einsatz bei niedrigeren und höheren
Temperaturen sind z. B. in EN 10269, ASTM F2281 und ASTM A 320/A 320 M enthalten.
Dieser Teil von ISO 898 gilt für Muttern:
- aus Kohlenstoffstahl oder legiertem Stahl;
- mit Regelgewinde M5 ≤ D ≤ M39;
- mit metrischem ISO-Gewinde nach ISO 68-1;
- mit Durchmesser-Steigungs-Kombinationen nach ISO 261;
- mit festgelegten Festigkeitsklassen einschließlich Prüfkraft;
- unterschiedlicher Muttertypen;
- mit einer Mindesthöhe m ≥ 0,45 D;
- mit einem Mindestaußendurchmesser oder einer Mindestschlüsselweite s ≥ 1,45 D (siehe auch Anhang
A);
- die zu Schrauben mit mechanischen Eigenschaften nach ISO 898-1 passen.
ANMERKUNG 3 Muttern mit Feingewinde sind in ISO 898-6 festgelegt.
Zu feuerverzinkten Schraubenverbindungen mit überschnittenen Muttern siehe außerdem ISO 10684.
Er legt keine Anforderungen für Eigenschaften fest wie:
- Sicherungseigenschaften (siehe ISO 2320);
- Drehmoment/Vorspannkraft (siehe ISO 16047 für entsprechende Prüfverfahren); (...)

Caractéristiques mécaniques des éléments de fixation en acier au carbone et en acier allié - Partie 2: Écrous de classes de qualité spécifiées - Filetages à pas gros et filetages à pas fin (ISO 898-2:2012)

La présente partie de l'ISO 898 spécifie les caractéristiques mécaniques et physiques des écrous à filetages
à pas gros et filetages à pas fin, en acier au carbone et en acier allié, lorsqu'ils sont soumis à essai dans une
plage de températures ambiantes de 10 °C à 35 °C.
Les écrous satisfaisant aux exigences de la présente partie de l'ISO 898 sont évalués dans cette plage de
températures ambiantes. Il se peut qu'ils ne conservent pas les caractéristiques mécaniques et physiques
spécifiées à des températures plus élevées et/ou plus basses.
NOTE 1 Les écrous satisfaisant aux exigences de la présente partie de l'ISO 898 ont été utilisés pour des applications
entre −50 °C et +150 °C. Il est de la responsabilité des utilisateurs de consulter un expert en matériaux de fixation pour les
températures situées hors de la plage allant de −50 °C à +150 °C et jusqu'à une température maximale de +300 °C afin de
déterminer les choix appropriés pour une application donnée.
NOTE 2 Des informations sur la sélection et l'application des aciers pour une utilisation à basses et hautes températures
sont données par exemple dans l'EN 10269, l'ASTM F2281 et l'ASTM A320/A320M.
La présente partie de l'ISO 898 s'applique aux écrous:
a) fabriqués en acier au carbone ou en acier allié;
b) à filetage à pas gros M5 ≤ D ≤ M39, et à filetage à pas fin M8×1 ≤ D ≤ M39×3;
c) à filetage métrique ISO triangulaire conforme à l'ISO 68‑1;
d) à combinaisons diamètre/pas conformes à l'ISO 261 et ISO 262;
e) de classes de qualité spécifiées, comprenant la charge d'épreuve;
f) de différents styles: écrous bas, écrous normaux et écrous hauts;
g) de hauteur minimale m ≥ 0,45D;
h) de diamètre extérieur ou de dimensions des surplats minimum s ≥ 1,45D (voir aussi Annexe A);
i) conçus pour être utilisés avec des vis, goujons et tiges filetées de classes de qualité conformes à l'ISO 898‑1.
Pour les écrous galvanisés à chaud, voir l'ISO 10684.
La présente partie de l'ISO 898 ne spécifie pas d'exigence pour les caractéristiques telles que:
— l'autofreinage (voir l'ISO 2320);
— la relation couple/tension (voir l'ISO 16047 pour la méthode d'essai);
— la soudabilité;
— la résistance à la corrosion.

Mehanske lastnosti veznih elementov, narejenih iz ogljikovega jekla in jeklene zlitine - 2. del: Matice z določenimi razredi trdnosti - Grobi in fini navoj (ISO 898-2:2012)

Ta del standarda ISO 898 določa mehanske in fizikalne lastnosti matic z grobim in finim navojem, izdelanih iz ogljikovega jekla ter jeklene zlitine, kadar se preskušajo pri temperaturi okolja od 10 °C do 35 °C. Matice, ki izpolnjujejo zahteve iz tega dela standarda ISO 898, se ovrednotijo pri tem temperaturnem razponu okolja. Možno je, da matice pri višjih in/ali nižjih temperaturah ne ohranijo določenih mehanskih in fizikalnih lastnosti.

General Information

• Status: Withdrawn
• Public Enquiry End Date: 09-Jun-2010
• Publication Date: 15-May-2012
• Withdrawal Date: 09-Nov-2022
• ICS: 21.060.20 - Nuts
• Technical Committee: ISEL - Mechanical elements
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 10-Nov-2022
• Due Date: 03-Dec-2022
• Completion Date: 10-Nov-2022
• Directive: 87/404/EEC - Simple pressure vessels
• Ref Project: EN ISO 898-2:2012 - Mechanical properties of fasteners made of carbon steel and alloy steel - Part 2: Nuts with specified property classes - Coarse thread and fine pitch thread (ISO 898-2:2012)

Relations

• Replaced By: SIST EN ISO 898-2:2022 - Fasteners - Mechanical properties of fasteners made of carbon steel and alloy steel - Part 2: Nuts with specified property classes (ISO 898-2:2022)
• Effective Date: 09-Nov-2022
• Replaces: SIST EN 20898-2:1996 - Mechanical properties of fasteners - Part 2: Nuts with specified proof load values - Coarse thread (ISO 898-2:1992)
• Effective Date: 01-Jul-2012
• Replaces: SIST EN ISO 898-6:1996 - Mechanical properties of fasteners - Part 6: Nuts with specified proof load values - Fine pitch thread (ISO 898-6:1994)
• Effective Date: 01-Jul-2012

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 898-2:2012
01-julij-2012
1DGRPHãþD
SIST EN 20898-2:1996
SIST EN ISO 898-6:1996
0HKDQVNHODVWQRVWLYH]QLKHOHPHQWRYQDUHMHQLKL]RJOMLNRYHJDMHNODLQMHNOHQH
]OLWLQHGHO0DWLFH]GRORþHQLPLUD]UHGLWUGQRVWL*URELLQILQLQDYRM,62

Mechanical properties of fasteners made of carbon steel and alloy steel - Part 2: Nuts
with specified property classes - Coarse thread and fine pitch thread (ISO 898-2:2012)
Mechanische Eigenschaften von Verbindungselementen aus Kohlenstoffstahl und
legiertem Stahl - Teil 2: Muttern mit festgelegten Festigkeitsklassen - Regelgewinde und
Feingewinde (ISO 898-2:2012)
Caractéristiques mécaniques des éléments de fixation en acier au carbone et en acier
allié - Partie 2: Écrous de classes de qualité spécifiées - Filetages à pas gros et filetages
à pas fin (ISO 898-2:2012)
Ta slovenski standard je istoveten z: EN ISO 898-2:2012
ICS:
21.060.20 Matice Nuts
SIST EN ISO 898-2:2012 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 898-2:2012

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SIST EN ISO 898-2:2012


EUROPEAN STANDARD
EN ISO 898-2

NORME EUROPÉENNE

EUROPÄISCHE NORM
March 2012
ICS 21.060.20 Supersedes EN 20898-2:1993, EN ISO 898-6:1995
English Version
Mechanical properties of fasteners made of carbon steel and
alloy steel - Part 2: Nuts with specified property classes - Coarse
thread and fine pitch thread (ISO 898-2:2012)
Caractéristiques mécaniques des éléments de fixation en Mechanische Eigenschaften von Verbindungselementen
acier au carbone et en acier allié - Partie 2: Écrous de aus Kohlenstoffstahl und legiertem Stahl - Teil 2: Muttern
classes de qualité spécifiées - Filetages à pas gros et mit festgelegten Festigkeitsklassen - Regelgewinde und
filetages à pas fin (ISO 898-2:2012) Feingewinde (ISO 898-2:2012)
This European Standard was approved by CEN on 14 March 2012.

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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 898-2:2012: E
worldwide for CEN national Members.

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SIST EN ISO 898-2:2012
EN ISO 898-2:2012 (E)
Contents Page
Foreword .3

2

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SIST EN ISO 898-2:2012
EN ISO 898-2:2012 (E)
Foreword
This document (EN ISO 898-2:2012) has been prepared by Technical Committee ISO/TC 2 "Fasteners" in
collaboration with Technical Committee CEN/TC 185 “Fasteners” the secretariat of which is held by DIN.
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 September 2012, and conflicting national standards shall be
withdrawn at the latest by September 2012.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 20898-2:1993, EN ISO 898-6:1995.
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, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 898-2:2012 has been approved by CEN as a EN ISO 898-2:2012 without any modification.

3

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SIST EN ISO 898-2:2012

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SIST EN ISO 898-2:2012
INTERNATIONAL ISO
STANDARD 898-2
Third edition
2012-03-15
Mechanical properties of fasteners made
of carbon steel and alloy steel —
Part 2:
Nuts with specified property classes —
Coarse thread and fine pitch thread
Caractéristiques mécaniques des éléments de fixation en acier au
carbone et en acier allié —
Partie 2: Écrous de classes de qualité spécifiées — Filetages à pas
gros et filetages à pas fin
Reference number
ISO 898-2:2012(E)
©
ISO 2012

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SIST EN ISO 898-2:2012
ISO 898-2:2012(E)
COPYRIGHT PROTECTED DOCUMENT
© 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
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved

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SIST EN ISO 898-2:2012
ISO 898-2:2012(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 2
3 Symbols . 2
4 Designation systems . 2
4.1 Designation of nut styles . 2
4.2 Designation of property classes . 2
4.3 Ranges of nominal diameters in relation to nut style and property class . 3
5 Design of bolt and nut assemblies . 3
6 Materials . 4
7 Mechanical properties . 5
8 Inspection . 8
8.1 Manufacturer’s inspection . 8
8.2 Supplier’s inspection . 8
8.3 Purchaser’s inspection . 8
9 Test methods . 9
9.1 Proof load test . 9
9.2 Hardness test . 11
9.3 Surface integrity inspection .13
10 Marking .13
10.1 General .13
10.2 Identification mark of the manufacturer .13
10.3 Marking of property classes .13
10.4 Identification .14
10.5 Marking of left-hand thread .15
10.6 Marking of packages .15
Annex A (informative) Design principles of nuts .16
Annex B (informative) Thread dimensions for the test mandrel .19
Bibliography .21
© ISO 2012 – All rights reserved iii

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SIST EN ISO 898-2:2012
ISO 898-2:2012(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.
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 898-2 was prepared by Technical Committee ISO/TC 2, Fasteners, Subcommittee SC 12, Fasteners with
metric internal thread.
This third edition cancels and replaces the second edition (ISO 898-2:1992) and ISO 898-6:1994, which have
been technically revised.
ISO 898 consists of the following parts, under the general title Mechanical properties of fasteners made of
carbon steel and alloy steel:
— Part 1: Bolts, screws and studs with specified property classes — Coarse thread and fine pitch thread
— Part 2: Nuts with specified property classes — Coarse thread and fine pitch thread
— Part 5: Set screws and similar threaded fasteners with specified hardness classes — Coarse thread and
fine pitch thread
1)
— Part 7: Torsional test and minimum torques for bolts and screws with nominal diameters 1 mm to 10 mm
1) It is intended that, upon revision, the main element of the title of Part 7 will be aligned with the main element of the title
of Part 1.
iv © ISO 2012 – All rights reserved

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SIST EN ISO 898-2:2012
INTERNATIONAL STANDARD ISO 898-2:2012(E)
Mechanical properties of fasteners made of carbon steel and
alloy steel —
Part 2:
Nuts with specified property classes — Coarse thread and
fine pitch thread
1 Scope
This part of ISO 898 specifies mechanical and physical properties of nuts with coarse thread and fine pitch
thread made of carbon steel and alloy steel when tested at an ambient temperature range of 10 °C to 35 °C.
Nuts conforming to the requirements of this part of ISO 898 are evaluated at that ambient temperature range.
It is possible that they do not retain the specified mechanical and physical properties at elevated and/or lower
temperatures.
NOTE 1 Nuts conforming to the requirements of this part of ISO 898 have been used in applications
ranging from –50 °C to +150 °C. It is the responsibility of users to consult an experienced fastener materials expert
for temperatures outside the range of –50 °C to +150 °C and up to a maximum temperature of +300°C to determine
appropriate choices for a given application.
NOTE 2 Information for the selection and application of steels for use at lower and elevated temperatures is given for
instance in EN 10269, ASTM F2281 and in ASTM A320/A320M.
This part of ISO 898 is applicable to nuts:
a) made of carbon steel or alloy steel;
b) with coarse thread M5 ≤ D ≤ M39, and fine pitch thread M8×1 ≤ D ≤ M39×3;
c) with triangular ISO metric thread according to ISO 68-1;
d) with diameter/pitch combinations according to ISO 261 and ISO 262;
e) with specified property classes, including proof load;
f) with different nut styles: thin nuts, regular nuts and high nuts;
g) with minimum height m ≥ 0,45D;
h) with a minimum outside diameter or width across flats s ≥ 1,45D (see Annex A);
i) able to mate with bolts, screws and studs with property classes according to ISO 898-1.
For hot dip galvanized nuts, see ISO 10684.
This part of ISO 898 does not specify requirements for properties such as:
— prevailing torque properties (see ISO 2320);
— torque/clamp force properties (see ISO 16047 for test method);
— weldability;
— corrosion resistance.
© ISO 2012 – All rights reserved 1

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SIST EN ISO 898-2:2012
ISO 898-2:2012(E)
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 6157-2, Fasteners — Surface discontinuities — Part 2: Nuts
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 (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 7500-1, Metallic materials — Verification of static uniaxial testing machines — Part 1: Tension/compression
testing machines — Verification and calibration of the force-measuring system
ISO 16426, Fasteners — Quality assurance system
3 Symbols
For the purposes of this document, the following symbols apply.
D nominal thread diameter of the nut, in millimetres
d hole diameter of the grip, in millimetres
h
F load, in newtons
h thickness of the grip, in millimetres
m height of the nut, in millimetres
P pitch of the thread, in millimetres
s width across flats, in millimetres
4 Designation systems
4.1 Designation of nut styles
This part of ISO 898 specifies requirements for three styles of nuts according to their height:
— style 2: high nut with minimum height m ≈ 0,9D or m > 0,9D; see Table A.1;
min min
— style 1: regular nut with minimum height m ≥ 0,8D; see Table A.1;
min
— style 0: thin nut with minimum height 0,45D ≤ m < 0,8D.
min
4.2 Designation of property classes
4.2.1 General
The marking and labelling of nuts with property classes shall be as specified in Clause 10 for only those nuts
which meet all applicable requirements of this part of ISO 898.
2 © ISO 2012 – All rights reserved

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SIST EN ISO 898-2:2012
ISO 898-2:2012(E)
4.2.2 Regular nuts (style 1) and high nuts (style 2)
The symbol for property classes of regular nuts (style 1) and high nuts (style 2) consists of one number. It
corresponds to the number to the left of the appropriate maximum property class of bolts, screws and studs
with which they can be mated.
4.2.3 Thin nuts (style 0)
The symbol for property classes of thin nuts (style 0) consists of two numbers, specified in the following ways:
a) the first number is zero, indicating that the loadability of the nut is reduced in comparison with the loadability
of a regular nut or a high nut according to 4.2.2 and therefore thread stripping can occur when overloaded;
b) the second number corresponds to 1/100 of the nominal stress under proof load on a hardened test
mandrel, in megapascals.
4.3 Ranges of nominal diameters in relation to nut style and property class
The ranges of nominal diameters in relation to nut style and property class are as given in Table 1.
Table 1 — Ranges of nominal diameters in relation to nut style and property class
Property class Range of nominal diameters, D
Regular nut (style 1) High nut (style 2) Thin nut (style 0)
M5 ≤ D ≤ M39
04 — —
M8×1 ≤ D ≤ M39×3
M5 ≤ D ≤ M39
05 — —
M8×1 ≤ D ≤ M39×3
M5 ≤ D ≤ M39
5 — —
M8×1 ≤ D ≤ M39×3
M5 ≤ D ≤ M39
6 — —
M8×1 ≤ D ≤ M39×3
M5 ≤ D ≤ M39 M5 < D ≤ M39
8 —
M8×1 ≤ D ≤ M39×3 M8×1 ≤ D ≤ M39×3
9 — M5 ≤ D ≤ M39 —
M5 ≤ D ≤ M39 M5 ≤ D ≤ M39
10 —
M8×1 ≤ D ≤ M16×1,5 M8×1 ≤ D ≤ M39×3
M5 ≤ D ≤ M39
12 M5 ≤ D ≤ M16 —
M8×1 ≤ D ≤ M16×1,5
5 Design of bolt and nut assemblies
Explanations of basic design principles of nuts and loadability of bolted assemblies are given in Annex A.
Regular nuts (style 1) and high nuts (style 2) shall be mated with externally threaded fasteners according to
Table 2. However, nuts of a higher property class may replace nuts of a lower property class.
© ISO 2012 – All rights reserved 3

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SIST EN ISO 898-2:2012
ISO 898-2:2012(E)
Table 2 — Combination of regular nuts (style 1) and high nuts (style 2) with bolt property classes
Maximum property class of mating
Nut property class
bolt, screw and stud
5 5.8
6 6.8
8 8.8
9 9.8
10 10.9
12 12.9/12.9
A decrease of thread stripping strength occurs for nuts with a fundamental deviation greater than zero for
tolerance class 6H (such as hot dip galvanized nuts: 6AZ, 6AX). Thin nuts (style 0) have a reduced loadability
compared to regular nuts or high nuts, and are not designed to provide resistance to thread stripping.
Thin nuts used as jam nuts should be assembled together with a regular nut or a high nut. In assemblies with
jam nut, the thin nut is first tightened against the assembled parts and then the regular or high nut is tightened
against the thin nut.
6 Materials
Table 3 specifies materials and heat treatment for the different property classes of nuts.
Nuts with coarse thread and property classes 05, 8 [regular nuts (style 1) with D > M16], 10 and 12 shall be
quenched and tempered.
Nuts with fine pitch thread and property classes 05, 6 (with D > M16), 8 [regular nuts (style 1)], 10 and 12 shall
be quenched and tempered.
The chemical composition shall be assessed in accordance with the relevant International Standards.
4 © ISO 2012 – All rights reserved

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SIST EN ISO 898-2:2012
ISO 898-2:2012(E)
Table 3 — Steels
Chemical composition limit
a
(cast analysis %)
Material and nut heat
Property class
treatment
C Mn P S
max. min. max. max.
c d
04 Carbon steel 0,58 0,25 0,060 0,150
c e
05 Carbon steel, QT 0,58 0,30 0,048 0,058
b d
5 Carbon steel 0,58 — 0,060 0,150
b d
6 Carbon steel 0,58 — 0,060 0,150
d
8 High nut (style 2) Carbon steel 0,58 0,25 0,060 0,150
d
8 Regular nut (style 1) D ≤ M16 Carbon steel 0,58 0,25 0,060 0,150
c e
8 Regular nut (style 1) D > M16 Carbon steel, QT 0,58 0,30 0,048 0,058
d
9 Carbon steel 0,58 0,25 0,060 0,150
c e
10 Carbon steel, QT 0,58 0,30 0,048 0,058
c e
12 Carbon steel, QT 0,58 0,45 0,048 0,058
b d
04 Carbon steel 0,58 0,25 0,060 0,150
c e
05 Carbon steel, QT 0,58 0,30 0,048 0,058
b d
5 Carbon steel 0,58 — 0,060 0,150
b d
6 D ≤ M16 Carbon steel 0,58 — 0,060 0,150
b e
6 D > M16 Carbon steel; QT 0,58 0,30 0,048 0,058
d
8 High nut (style 2) Carbon steel 0,58 0,25 0,060 0,150
c e
8 Regular nut (style 1) Carbon steel, QT 0,58 0,30 0,048 0,058
c e
10 Carbon steel, QT 0,58 0,30 0,048 0,058
c e
12 Carbon steel, QT 0,58 0,45 0,048 0,058
QT = Quenched and tempered nuts.
“—“   No limit specified.
a
In case of dispute, the product analysis applies.
b
Nuts of these property classes may be manufactured from free-cutting steel upon agreement between the purchaser
and the manufacturer; in such a case, sulfur, phosphorus and lead are permissible with the following maximum contents:
S: 0,34 %; P: 0,11 %; Pb: 0,35%.
c
Alloying elements may be added, provided the mechanical properties required in Clause 7 are fulfilled.
d
This may be quenched and tempered at the manufacturer’s discretion.
e
For materials of these property classes, there shall be sufficient hardenability to ensure a structure consisting of approximately
90 % martensite in the “as-hardened” condition before tempering in the threaded area of the nut as specified in Figure 3.
NOTE It is intended that national regulations for the restriction or prohibition of certain chemical elements be taken
into account in the countries or regions concerned.
7 Mechanical properties
When tested by the methods specified in Clause 9, the nuts of the specified property class shall meet, at
ambient temperature, the requirements for the proof load (see Tables 4 and 5) and for the hardness (see Tables
6 and 7), regardless of which tests are performed during manufacturing or final inspection.
For nuts which are not quenched and tempered, 9.2.4.2 additionally applies.
© ISO 2012 – All rights reserved 5
Thread
Fine pitch thread Coarse thread

---------------------- Page: 15 ----------------------

SIST EN ISO 898-2:2012
ISO 898-2:2012(E)
Table 4 — Proof load values for nuts with coarse thread
a
Proof load , N
Thread Pitch
Property class
D P
04 05 5 6 8 9 10 12
M5 0,8 5 400 7 100 8 250 9 500 12 140 13 000 14 800 16 300
M6 1 7 640 10 000 11 700 13 500 17 200 18 400 20 900 23 100
M7 1 11 000 14 500 16 800 19 400 24 700 26 400 30 100 33 200
M8 1,25 13 900 18 300 21 600 24 900 31 800 34 400 38 100 42 500
M10 1,5 22 000 29 000 34 200 39 400 50 500 54 500 60 300 67 300
M12 1,75 32 000 42 200 51 400 59 000 74 200 80 100 88 500 100 300
M14 2 43 700 57 500 70 200 80 500 101 200 109 300 120 800 136 900
M16 2 59 700 78 500 95 800 109 900 138 200 149 200 164 900 186 800
M18 2,5 73 000 96 000 121 000 138 200 176 600 176 600 203 500 230 400
M20 2,5 93 100 122 500 154 400 176 400 225 400 225 400 259 700 294 000
M22 2,5 115 100 151 500 190 900 218 200 278 800 278 800 321 200 363 600
M24 3 134 100 176 500 222 400 254 200 324 800 324 800 374 200 423 600
M27 3 174 400 229 500 289 200 330 500 422 300 422 300 486 500 550 800
M30 3,5 213 200 280 500 353 400 403 900 516 100 516 100 594 700 673 200
M33 3,5 263 700 347 000 437 200 499 700 638 500 638 500 735 600 832 800
M36 4 310 500 408 500 514 700 588 200 751 600 751 600 866 000 980 400
M39 4 370 900 488 000 614 900 702 700 897 900 897 900 1 035 000 1 171 000
a
For the application of thin nuts, it should be considered that the stripping load is lower than the proof load of a nut with full
loadability (see Annex A).
6 © ISO 2012 – All rights reserved

---------------------- Page: 16 ----------------------

SIST EN ISO 898-2:2012
ISO 898-2:2012(E)
Table 5 — Proof load values for nuts with fine pitch thread
a
Proof load , N
Thread
Property class
D × P
04 05 5 6 8 10 12
M8×1 14 900 19 600 27 000 30 200 37 400 43 100 47 000
M10×1,25 23 300 30 600 44 200 47 100 58 400 67 300 73 400
M10×1 24 500 32 200 44 500 49 700 61 600 71 000 77 400
M12×1,5 33 500 44 000 60 800 68 700 84 100 97 800 105 700
M12×1,25 35 000 46 000 63 500 71 800 88 000 102 200 110 500
M14×1,5 47 500 62 500 86 300 97 500 119 400 138 800 150 000
M16×1,5 63 500 83 500 115 200 130 300 159 500 185 400 200 400
M18×2 77 500 102 000 146 900 177 500 210 100 220 300 —
M18×1,5 81 700 107 500 154 800 187 000 221 500 232 200 —
M20×2 98 000 129 000 185 800 224 500 265 700 278 600 —
M20×1,5 103 400 136 000 195 800 236 600 280 200 293 800 —
M22×2 120 800 159 000 229 000 276 700 327 500 343 400 —
M22×1,5 126 500 166 500 239 800 289 700 343 000 359 600 —
M24×2 145 900 192 000 276 500 334 100 395 500 414 700 —
M27×2 188 500 248 000 351 100 431 500 510 900 535 700 —
M30×2 236 000 310 500 447 100 540 300 639 600 670 700 —
M33×2 289 200 380 500 547 900 662 100 783 800 821 900 —
M36×3 328 700 432 500 622 800 804 400 942 800 934 200 —
M39×3 391 400 515 000 741 600 957 900 1 123 000 1 112 000 —
a
For the application of thin nuts, it should be considered that the stripping load is lower than the proof load of a nut with full
loadability, see Annex A.
Table 6 — Hardness properties for nuts with coarse thread
Property class
Thread
04 05 5 6 8 9 10 12
D Vickers hardness, HV
min. max. min. max. min. max. min. max. min. max. min. max. min. max. min. max.
c
M5 ≤ D ≤ M16 130 150 200 302 295
188 302 272 353 302 302 188 302 272 353 353
a b
M16 < D ≤ M39 146 170 233 353 272
Brinell hardness, HB

min. max. min. max. min. max. min. max. min. max. min. max. min. max. min. max.
c
M5 ≤ D ≤ M16 124 143 190 287 280
179 287 259 336 287 287 179 287 259 336 336
a b
M16 < D ≤ M39 139 162 221 336 259
Rockwell hardness, HRC

min. max. min. max. min. max. min. max. min. max. min. max. min. max. min. max.
c
M5 ≤ D ≤ M16 — 30 29
— 30 26 36 — 30 — 30 — 30 26 36 36
b
M16 < D ≤ M39 — 36 26
Surface integrity shall be in accordance with ISO 6157-2.
Vickers hardness test is the reference method for acceptance (see 9.2.4).
a
Minimum value for high nuts (style 2): 180 HV (171 HB).
b
Maximum value for high nuts (style 2): 302 HV (287 HB; 30 HRC).
c
Minimum value for high nuts (style 2): 272 HV (259 HB; 26 HRC).
© ISO 2012 – All rights reserved 7

---------------------- Page: 17 ----------------------

SIST EN ISO 898-2:2012
ISO 898-2:2012(E)
Table 7 — Hardness properties for nuts with fine pitch thread
Property class
Thread
04 05 5 6 8 10 12
Vickers hardness, HV
D × P
min. max. min. max. min. max. min. max. min. max. min. max. min. max.
a b c
M8×1 ≤ D ≤ M16×1,5 175 188 302 250 353 295 295 353
188 302 272 353 302 353
M16×1,5 < D ≤ M39×3 190 233 295 353 260 — —
Brinell hardness, HB
min. max. min. max. min. max. min. max. min. max. min. max. min. max.
a b c
M8×1 ≤ D ≤ M16×1,5 166 179 238 336 280 280 336
179 287 259 336 287 287 336
M16×1,5 < D ≤ M39×3 181 221 280 336 247 — —

Rockwell hardness, HRC
min. max. min. max. min. max. min. max. min. max. min. max. min. max.
a b c
M8×1 ≤ D ≤ M16×1,5 — — 22,2 36 29 29 36
— 30 26 36 30 30 36
M16×1,5 < D ≤ M39×3 — — 29,2 36 24 — —
Surface integrity shall be in accordance with ISO 6157-2.
The Vickers hardness test is the reference method for acceptance (see 9.2.4).
a
Minimum value for high nuts (style 2): 195 HV (185 HB).
b
Maximum value for high nuts (style 2): 302 HV (287 HB; 30 HRC).
c
Minimum value for high nuts (style 2): 250 HV (238 HB; 22,2 HRC).
8 Inspection
8.1 Manufacturer’s inspection
This part of ISO 898 does not mandate which of the tests the manufacturer shall perform on each manufacturing
lot. It is the responsibility of the manufacturer to apply suitable methods of his choice, such as in-process testing
or inspection to ensure that the manufactured lot does indeed conform to all of the specified requirements. For
additional information, see ISO 16426.
In case of dispute, the test methods according to Clause 9 shall apply.
8.2 Supplier’s inspection
The supplier tests the nuts which he provides using methods of their choice (periodic evaluation of the
manuf
...