SIST EN ISO 3506-2:2011

Mechanical properties of corrosion-resistant stainless steel fasteners - Part 2: Nuts (ISO 3506-2:2009)

This part of ISO 3506 specifies the mechanical properties of nuts made of austenitic, martensitic and ferritic steel grades of corrosion-resistant stainless steels, when tested over an ambient temperature range of 10 °C to 35 °C. Properties vary at higher or lower temperatures.
This part of ISO 3506 applies to nuts:
⎯with nominal thread diameter D u 39 mm;
⎯of triangular ISO metric threads with diameters and pitches in accordance with ISO 68-1, ISO 261 and ISO 262;
⎯of any shape;
⎯with width across flats as specified in ISO 272;
⎯with nominal heights m W 0,5D.
It does not apply to nuts requiring properties such as
⎯locking abilities, and
⎯weldability.
NOTE The designation system of this part of ISO 3506 can be used for sizes outside the limits given in this clause (e.g. D 39 mm), provided that all applicable mechanical and physical requirements of the property classes are met.
This part of ISO 3506 does not define corrosion or oxidation resistance in particular environments. However, some information on materials for particular environments is given in Annex D. Regarding definitions of corrosion and corrosion resistance, see ISO 8044.
The aim of this part of ISO 3506 is the classification of corrosion-resistant stainless steel nuts into property classes. Some materials can be used at temperatures down to −200 °C, some can be used at temperatures up to 800 °C in air. Information on the influence of temperature on mechanical properties is found in Annex E.
Corrosion and oxidation performances and mechanical properties for use at elevated or sub-zero
temperatures can be agreed on between the user and the manufacturer in each particular case. Annex F shows how the risk of intergranular corrosion at elevated temperatures depends on the carbon content.
All austenitic stainless steel fasteners are normally non-magnetic in the annealed condition; after cold working, some magnetic properties can be evident (see Annex G).

Mechanische Eigenschaften von Verbindungselementen aus nichtrostenden Stählen - Teil 2: Muttern (ISO 3506-2:2009)

Dieser Teil von ISO 3506 legt die mechanischen Eigenschaften von Muttern aus austenitischen,
martensitischen und ferritischen nichtrostenden Stählen bei Prüfung in einem Umgebungstemperaturbereich
zwischen 10 °C und 35 °C fest. Die Eigenschaften verändern sich bei höheren oder tieferen Temperaturen.
prEN ISO 3506-2:2008 (D)
5
Dieser Teil von ISO 3506 gilt für Muttern
- mit Gewindenenndurchmessern d ≤ 39 mm;
- mit metrischen ISO-Gewinden mit Durchmessern (d) und Steigungen (P) nach ISO 68-1, ISO 261 und
ISO 262;
- mit beliebiger Form;
- mit Schlüsselweiten nach ISO 272;
- mit Nennhöhen m ≥ 0,5 d.
Sie gilt nicht für Muttern mit besonderen Anforderungen wie
⎯ Sicherungsverhalten;
⎯ Schweißbarkeit.
ANMERKUNG Das Bezeichnungssystem in diesem Teil von ISO 3506 darf auch für Nenngrößen außerhalb der in
diesem Abschnitt angegebenen Grenzen (z. B. d > 39 mm) verwendet werden, vorausgesetzt alle der jeweiligen
Festigkeitsklasse zugeordneten mechanischen und physikalischen Anforderungen werden erfüllt.
Dieser Teil von ISO 3506 enthält keine Festlegungen über die Korrosion oder Korrosionsbeständigkeit in
besonderen Umgebungen, jedoch sind einige Angaben über Werkstoffe für bestimmte Umgebungen in
Anhang D enthalten. Für Definitionen zu Korrosion und Korrosionsbeständigkeit siehe ISO 8044.
Zweck dieses Teils von ISO 3506 ist eine Einteilung von Muttern aus nichtrostenden Stählen in
Festigkeitsklassen. Einige Werkstoffe können bei Temperaturen bis −200 °C, einige an Luft bei Temperaturen
bis +800 °C eingesetzt werden. Angaben über den Einfluss der Temperatur auf die mechanischen
Eigenschaften sind in Anhang E enthalten.
Anforderungen an die Korrosionsbeständigkeit und die mechanischen Eigenschaften für den Einsatz bei
höheren Temperaturen oder bei Temperaturen unter 0 °C müssen in jedem Einzelfall zwischen Anwender und
Hersteller vereinbart werden.

Caractéristiques mécaniques des éléments de fixation en acier inoxydable résistant à la corrosion - Partie 2: Écrous (ISO 3506-2:2009)

L'ISO 3506-2:2009 spécifie les caractéristiques mécaniques des écrous constitués d'aciers inoxydables austénitiques, martensitiques et ferritiques résistant à la corrosion et soumis à essai à une température ambiante comprise entre 10 °C et 35 °C. Ces caractéristiques varient selon la valeur plus ou moins élevée de la température.
L'ISO 3506-2:2009 s'applique aux écrous
de diamètre nominal de filetage d ≤ 39 mm,
à filetage métrique ISO triangulaire dont le diamètre et le pas sont conformes à l'ISO 68-1, à l'ISO 261 et à l'ISO 262,
de forme quelconque,
avec des cotes surplats telles que spécifiées dans l'ISO 272, et
dont la hauteur nominale m ≥ 0,5d.
Elle ne s'applique pas aux écrous possédant des caractéristiques spéciales telles que la capacité de freinage et la soudabilité.

Mehanske lastnosti veznih elementov iz nerjavnega jekla - 2. del: Matice (ISO 3506-2:2009)

Ta del ISO 3506 določa mehanske lastnosti matic, narejenih iz avstenitnih, martenzitnih in feritnih vrst nerjavnega jekla, odpornega proti koroziji, pri preskušanju v območju okoljske temperature med 10 °C in 35 °C. Lastnosti se spreminjajo glede na višje ali nižje temperature.
Ta del ISO 3506 velja za matice:
⎯ z nazivnim premerom navoja D u 39 mm;
⎯ s trikotnimi metrskimi navoji ISO s premeri in nakloni v skladu z ISO 68-1, ISO 261 in ISO 262;
⎯ katere koli oblike;
⎯ s širino plošče, kot jo določa ISO 272;
⎯ z nazivnimi višinami m W 0,5 D.
Ne velja za matice s posebnimi lastnostmi:
⎯ zaklepne zmožnosti in
⎯ varivost.
OPOMBA: Sistem označevanja v tem delu ISO 3506 se lahko uporablja za velikosti zunaj omejitev, podanih v tej točki (npr. D  39 mm), če so izpolnjene veljavne mehanske in fizikalne zahteve lastnostnih razredov.
Ta del ISO 3506 ne opredeljuje odpornosti proti koroziji ali oksidaciji v določenih okoljih. Nekateri podatki o materialih za določena okolja so kljub temu navedeni v dodatku D. Za opredelitve korozije in odpornosti proti koroziji glej ISO 8044.
Namen tega dela ISO 3506 je razvrstitev matic iz nerjavnega jekla, odpornega proti koroziji, v lastnostne razrede. Nekateri materiali se lahko uporabljajo pri temperaturah zraka do najmanj −200 °C, drugi pa se lahko uporabljajo pri temperaturah do največ 800 °C. Podatki o vplivu temperature na mehanske lastnosti so navedeni v dodatku E.
O zmogljivostih, povezanih s korozijo in oksidacijo, in mehanskih lastnostih za uporabo pri povišanih temperaturah ali temperaturah pod nič se lahko dogovorita uporabnik in proizvajalec za vsak posamezen primer. Dodatek F prikazuje, kako je tveganje za interkristalno korozijo pri povišanih temperaturah odvisno od vsebnosti ogljika.
Vsi vezni elementi iz avstenitnega nerjavnega jekla so v nežarjenem stanju običajno nemagnetni; po hladni obdelavi so nekatere magnetne lastnosti očitne (glej dodatek G).

General Information

• Status: Withdrawn
• Public Enquiry End Date: 14-Nov-2008
• Publication Date: 08-May-2011
• Withdrawal Date: 11-May-2020
• ICS: 21.060.20 - Nuts
• Technical Committee: ISEL - Mechanical elements
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 12-May-2020
• Due Date: 04-Jun-2020
• Completion Date: 12-May-2020
• Ref Project: EN ISO 3506-2:2009 - Mechanical properties of corrosion-resistant stainless steel fasteners - Part 2: Nuts (ISO 3506-2:2009)

Relations

• Replaced By: SIST EN ISO 3506-2:2020 - Fasteners - Mechanical properties of corrosion-resistant stainless steel fasteners - Part 2: Nuts with specified grades and property classes (ISO 3506-2:2020)
• Effective Date: 11-May-2020
• Replaced By: SIST EN ISO 3506-2:2020 - Fasteners - Mechanical properties of corrosion-resistant stainless steel fasteners - Part 2: Nuts with specified grades and property classes (ISO 3506-2:2020)
• Effective Date: 08-Jun-2022
• Replaces: SIST EN ISO 3506-2:2001 - Mechanical properties of corrosion-resistant stainless-steel fasteners - Part 2: Nuts (ISO 3506-2:1997)
• Effective Date: 01-Jun-2011
• Replaces: SIST ISO 3506-2:2000 - Mechanical properties of corrosion-resistant stainless-steel fasteners -- Part 2: Nuts
• Effective Date: 01-May-2010
• Revised: SIST EN ISO 3506-2:2020 - Fasteners - Mechanical properties of corrosion-resistant stainless steel fasteners - Part 2: Nuts with specified grades and property classes (ISO 3506-2:2020)
• Effective Date: 11-Nov-2015
• Replaces: SIST EN ISO 3506-2:2001 - Mechanical properties of corrosion-resistant stainless-steel fasteners - Part 2: Nuts (ISO 3506-2:1997)
• Effective Date: 08-Jun-2022

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Mehanske lastnosti veznih elementov iz nerjavnega jekla - 2. del: Matice (ISO 3506-2:2009)Mechanische Eigenschaften von Verbindungselementen aus nichtrostenden Stählen - Teil 2: Muttern (ISO 3506-2:2009)Caractéristiques mécaniques des éléments de fixation en acier inoxydable résistant à la corrosion - Partie 2: Écrous (ISO 3506-2:2009)Mechanical properties of corrosion-resistant stainless steel fasteners - Part 2: Nuts (ISO 3506-2:2009)21.060.20MaticeNutsICS:Ta slovenski standard je istoveten z:EN ISO 3506-2:2009SIST EN ISO 3506-2:2011en,fr,de01-junij-2011SIST EN ISO 3506-2:2011SLOVENSKI
STANDARDSIST ISO 3506-2:2000SIST EN ISO 3506-2:20011DGRPHãþD



SIST EN ISO 3506-2:2011



EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN ISO 3506-2
November 2009 ICS 21.060.20 Supersedes EN ISO 3506-2:1997English Version
Mechanical properties of corrosion-resistant stainless steel fasteners - Part 2: Nuts (ISO 3506-2:2009)
Caractéristiques mécaniques des éléments de fixation en acier inoxydable résistant à la corrosion - Partie 2: Écrous (ISO 3506-2:2009)
Mechanische Eigenschaften von Verbindungselementen aus nichtrostenden Stählen - Teil 2: Muttern (ISO 3506-2:2009) This European Standard was approved by CEN on 24 October 2009.
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 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 Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, 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 and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2009 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 3506-2:2009: ESIST EN ISO 3506-2:2011



EN ISO 3506-2:2009 (E) 2 Contents Page Foreword .3 SIST EN ISO 3506-2:2011



EN ISO 3506-2:2009 (E) 3 Foreword This document (EN ISO 3506-2:2009) 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 May 2010, and conflicting national standards shall be withdrawn at the latest by May 2010. 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 ISO 3506-2:1997. 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, 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 and the United Kingdom. Endorsement notice The text of ISO 3506-2:2009 has been approved by CEN as a EN ISO 3506-2:2009 without any modification.
SIST EN ISO 3506-2:2011



SIST EN ISO 3506-2:2011



Reference numberISO 3506-2:2009(E)© ISO 2009
INTERNATIONAL STANDARD ISO3506-2Second edition2009-11-15Mechanical properties of corrosion-resistant stainless steel fasteners — Part 2: Nuts Caractéristiques mécaniques des éléments de fixation en acier inoxydable résistant à la corrosion — Partie 2: Écrous
SIST EN ISO 3506-2:2011



ISO 3506-2:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
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ISO 2009 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.
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ii © ISO 2009 – All rights reserved
SIST EN ISO 3506-2:2011



ISO 3506-2:2009(E) © ISO 2009 – All rights reserved iii Contents Page Foreword.iv Introduction.v 1 Scope.1 2 Normative references.2 3 Symbols.2 4 Designation, marking and finish.3 4.1 Designation.3 4.2 Marking.4 4.3 Finish.6 5 Chemical composition.6 6 Mechanical properties.7 7 Test methods.8 7.1 Hardness HB, HRC or HV.8 7.2 Proof load.8 Annex A (informative)
Description of the groups and grades of stainless steels.9 Annex B (informative)
Stainless steel composition specifications.12 Annex C (informative)
Stainless steels for cold heading and extruding.15 Annex D (informative)
Austenitic stainless steels with particular resistance to chloride induced stress corrosion.17 Annex E (informative)
Mechanical properties at elevated temperatures; application at low temperatures.18 Annex F (informative)
Time-temperature diagram of intergranular corrosion in austenitic stainless steels, grade A2 (18/8 steels).19 Annex G (informative)
Magnetic properties for austenitic stainless steels.20 Bibliography.21
SIST EN ISO 3506-2:2011



ISO 3506-2:2009(E) iv © ISO 2009 – All rights reserved 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 3506-2 was prepared by Technical Committee ISO/TC 2, Fasteners, Subcommittee SC 1, Mechanical properties of fasteners. This second edition cancels and replaces the first edition (ISO 3506-2:1997), which has been technically revised. ISO 3506 consists of the following parts, under the general title Mechanical properties of corrosion-resistant stainless steel fasteners: ⎯ Part 1: Bolts, screws and studs ⎯ Part 2: Nuts ⎯ Part 3: Set screws and similar fasteners not under tensile stress ⎯ Part 4: Tapping screws SIST EN ISO 3506-2:2011



ISO 3506-2:2009(E) © ISO 2009 – All rights reserved v Introduction In the preparation of this part of ISO 3506, special attention has been given to the fundamentally different property characteristics of the stainless steel fastener grades compared with those of carbon steel and low-alloy steel fasteners. Ferritic and austenitic stainless steels are strengthened only by cold working and consequently, the components do not have as homogeneous local material properties as hardened and tempered parts. These special features have been recognized in the elaboration of the property classes and the test procedures for mechanical properties. The latter differ from the carbon steel and low-alloy steel fastener test procedures with regard to the measurement of the stress at 0,2 % permanent strain (yield stress) and ductility (total elongation after fracture).
SIST EN ISO 3506-2:2011



SIST EN ISO 3506-2:2011



INTERNATIONAL STANDARD ISO 3506-2:2009(E) © ISO 2009 – All rights reserved 1 Mechanical properties of corrosion-resistant stainless steel fasteners — Part 2: Nuts 1 Scope This part of ISO 3506 specifies the mechanical properties of nuts made of austenitic, martensitic and ferritic steel grades of corrosion-resistant stainless steels, when tested over an ambient temperature range of 10 °C to 35 °C. Properties vary at higher or lower temperatures. This part of ISO 3506 applies to nuts: ⎯ with nominal thread diameter D u 39 mm; ⎯ of triangular ISO metric threads with diameters and pitches in accordance with ISO 68-1, ISO 261 and ISO 262; ⎯ of any shape; ⎯ with width across flats as specified in ISO 272; ⎯ with nominal heights m W 0,5D. It does not apply to nuts requiring properties such as ⎯ locking abilities, and ⎯ weldability. NOTE The designation system of this part of ISO 3506 can be used for sizes outside the limits given in this clause (e.g. D > 39 mm), provided that all applicable mechanical and physical requirements of the property classes are met. This part of ISO 3506 does not define corrosion or oxidation resistance in particular environments. However, some information on materials for particular environments is given in Annex D. Regarding definitions of corrosion and corrosion resistance, see ISO 8044. The aim of this part of ISO 3506 is the classification of corrosion-resistant stainless steel nuts into property classes. Some materials can be used at temperatures down to − 200 °C, some can be used at temperatures up to + 800 °C in air. Information on the influence of temperature on mechanical properties is found in Annex E. Corrosion and oxidation performances and mechanical properties for use at elevated or sub-zero temperatures can be agreed on between the user and the manufacturer in each particular case. Annex F shows how the risk of intergranular corrosion at elevated temperatures depends on the carbon content. SIST EN ISO 3506-2:2011



ISO 3506-2:2009(E) 2 © ISO 2009 – All rights reserved All austenitic stainless steel fasteners are normally non-magnetic in the annealed condition; after cold working, some magnetic properties can be evident (see Annex G). 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 68-1, ISO general purpose screw threads — Basic profile — Part 1: Metric screw threads ISO 261, ISO general purpose metric screw threads — General plan ISO 262, ISO general purpose metric screw threads — Selected sizes for screws, bolts and nuts ISO 272, Fasteners — Hexagon products — Widths across flats ISO 898-2, Mechanical properties of fasteners — Part 2: Nuts with specified proof load values — Coarse thread ISO 898-6, Mechanical properties of fasteners — Part 6: Nuts with specified proof load values — Fine pitch thread ISO 3651-1, Determination of resistance to intergranular corrosion of stainless steels — Part 1: Austenitic and ferritic-austenitic (duplex) stainless steels — Corrosion test in nitric acid medium by measurement of loss in mass (Huey test) ISO 3651-2, Determination of resistance to intergranular corrosion of stainless steels — Part 2: Ferritic, austenitic and ferritic-austenitic (duplex) stainless steels — Corrosion test in media containing sulfuric acid 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 16048, Passivation of corrosion-resistant stainless-steel fasteners ISO 16426, Fasteners — Quality assurance system 3 Symbols D nominal thread diameter m height of the nut (nominal value) P pitch of the thread ReL lower yield stress Rp0,2 stress at 0,2 % permanent strain s width across flats Sp stress under proof load µr permeability value in a magnetic field SIST EN ISO 3506-2:2011



ISO 3506-2:2009(E) © ISO 2009 – All rights reserved 3 4 Designation, marking and finish 4.1 Designation The designation system for stainless steel grades and property classes for nuts is given in Figure 1. The designation of the material consists of two blocks, which are separated by a hyphen. The first block designates the steel grade and the second block, the property class. The designation of the steel grade (first block) consists of the letters ⎯ A for austenitic steel, ⎯ C for martensitic steel, or ⎯ F for ferritic steel which indicates the group of steel and a digit, which indicates a range of chemical compositions within this steel group (see Table 1). The designation of the property class (second block) consists of two digits for nuts with height m W 0,8D (style 1 or style 2 or hexagon flange nuts), representing 1/10 of the stress under proof load, and three digits for nuts with height 0,5D u m < 0,8D (thin nuts/style 0), the first digit “0” indicating that the nut has a reduced loadability and the following digits representing 1/10 of the stress under proof load. The following are examples for the designation of material. EXAMPLE 1 A2-70 indicates: austenitic steel, cold worked, minimum 700 MPa stress under proof load (nut with m W 0,8D). EXAMPLE 2 C4-70 indicates: martensitic steel, hardened and tempered, minimum 700 MPa stress under proof load (nut with m W 0,8D). EXAMPLE 3 A2-035 indicates: austenitic steel, cold worked, minimum 350 MPa stress under proof load (nut with 0,5D u m < 0,8D). SIST EN ISO 3506-2:2011



ISO 3506-2:2009(E) 4 © ISO 2009 – All rights reserved
a The steel groups and steel grades classified in Figure 1 are described in Annex A and specified by the chemical composition given in Table 1. b Low carbon austenitic stainless steels with carbon content not exceeding 0,03 % may additionally be marked with an “L”. EXAMPLE A4L-80 c Nuts passivated in accordance with ISO 16048 may additionally be marked with a “P”.
EXAMPLE A4-80P Figure 1 — Designation system for stainless steel grades and property classes for nuts 4.2 Marking 4.2.1 General Nuts manufactured according to the requirements of this part of ISO 3506 shall be designated in accordance with the designation system described in 4.1 and marked in accordance with 4.2.2 and 4.2.3. However, the designation system described in 4.1 and the provisions for marking according to 4.2.3 shall be used only if all relevant requirements of this part of ISO 3506 are met. NOTE For marking of left-hand threads, see ISO 898-2. 4.2.2 Manufacturer's identification mark A manufacturer's identification mark shall be included during the manufacturing process on all nuts which are marked with a property class symbol, provided this is possible for technical reasons. Manufacturer's identification marking is also recommended on nuts which are not marked with a property class symbol. 4.2.3 Nuts All nuts of nominal thread diameter D W 5 mm shall be clearly marked in accordance with 4.1, Figure 1 and Figure 2 or Figure 3. The marking is mandatory and shall include the steel grade and property class. Marking SIST EN ISO 3506-2:2011



ISO 3506-2:2009(E) © ISO 2009 – All rights reserved 5 of only one nut face is acceptable and shall be by indentation only, when applied to the bearing surface of the nuts. Alternatively, marking on one side of the nuts is permissible.
Key 1 manufacturer's identification mark 2 steel grade 3 property class Figure 2 — Marking with material designation and manufacturer's identification mark
Key s width across flats Figure 3 — Alternative groove marking (for steel grades A2 and A4 only) When the marking is made with grooves (see Figure 3) and the property class is not indicated, property class 50 or 025 will apply.
It is possible that certain nuts would not fulfil the proof load requirements because of fine pitch thread or the geometry of the nut. These nuts may be marked with the steel grade, but shall not be marked with the property class. 4.2.4 Packages All packages for all types of nuts of all sizes shall be marked (e.g. through labelling). The marking or labelling shall include the manufacturer's and/or distributor's identification and the marking symbol for the steel grade and property class according to Figure 1 and the manufacturing lot number, as defined in ISO 16426. SIST EN ISO 3506-2:2011



ISO 3506-2:2009(E) 6 © ISO 2009 – All rights reserved 4.3 Finish Unless otherwise specified, nuts in accordance with this part of ISO 3506 shall be supplied clean and bright. For maximum corrosion resistance, passivation is recommended. When passivation is required, it shall be performed in accordance with ISO 16048. Nuts that are passivated may additionally be marked with the symbol “P” after the symbols for steel grade and property class (see footnote c of Figure 1). For nuts manufactured to a specific order, the additional marking should be applied to both the fastener and the label. For nuts delivered from stock, the additional marking should be applied to the label. 5 Chemical composition The chemical compositions of stainless steels suitable for nuts in accordance with this part of ISO 3506 are given in Table 1. NOTE The chemical compositions given in Table 1 correspond with the chemical compositions given in ISO 3506-1:2009, Table 1, for the relevant steel grades. The final choice of the chemical composition within the specified steel grade is at the discretion of the manufacturer, ot
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