EN ISO 4027:2026

Fasteners - Hexagon socket set screws with truncated cone point (ISO 4027:2026)

This document specifies the characteristics of hexagon socket set screws with truncated cone point, with metric coarse pitch threads M1,6 to M30 for steel and M1,6 to M24 for stainless steel, and with product grade A.
Set screws are not intended for use under tensile load.
If in certain cases other specifications are requested, hardness classes and stainless steel grades can be selected from ISO 898-5 or ISO 3506-3, and dimensional options from ISO 888, ISO 965-1 or ISO 4753.

Verbindungselemente - Gewindestifte mit Innensechskant mit abgeflachter Spitze (ISO 4027:2026)

Dieses Dokument legt die Eigenschaften von Gewindestiften mit Innensechskant mit abgeflachter Spitze mit metrischen Regelgewinden von M1,6 bis M30 für Stahl und M1,6 bis M24 für nichtrostenden Stahl in der Produktklasse A fest.
Gewindestifte sind nicht für die Anwendung unter Zugspannung vorgesehen.
Werden in besonderen Fällen andere Festlegungen benötigt, können Härteklassen und Stahlsorten aus ISO 898 5 oder ISO 3506 3, und maßbezogene Optionen aus ISO 888, ISO 965 1 oder ISO 4753 ausgewählt werden.

Fixations - Vis sans tête à six pans creux, à bout tronconique (ISO 4027:2026)

Le présent document spécifie les caractéristiques des vis sans tête à six pans creux à bout tronconique, à filetage métrique à pas gros M1,6 à M30 pour l'acier et M1,6 à M24 pour l'acier inoxydable, et de grade A.
Les vis sans tête ne sont pas prévues pour être utilisées sous charge de traction.
Si dans certains cas d’autres spécifications sont requises, les classes de dureté et les grades d’acier inoxydable peuvent être choisis dans l’ISO 898-5 ou l’ISO 3506-3, et les options dimensionnelles dans l'ISO 888, l'ISO 965-1 ou l'ISO 4753.

Vezni elementi - Navojni zatiči z notranjim šestkotnikom in končino s skrajšano konico (ISO 4027:2026)

Ta dokument določa lastnosti imbus čepov z odrezano konično konico, z metričnimi grobimi navoji M1,6 do M30 za jeklo in M1,6 do M24 za nerjavno jeklo, ter s kakovostjo izdelka A.
Čepi niso namenjeni uporabi pod natezno obremenitvijo.
Če so v določenih primerih zahtevane druge specifikacije, se lahko razredi trdote in vrste nerjavnega jekla izberejo iz ISO 898-5 ali ISO 3506-3, dimenzijske možnosti pa iz ISO 888, ISO 965-1 ali ISO 4753.

General Information

• Status: Published
• Publication Date: 24-Feb-2026
• ICS: 21.060.10 - Bolts, screws, studs
• Technical Committee: CEN/TC 185 - Threaded and nonthreaded mechanical fasteners and accessories
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 25-Feb-2026
• Completion Date: 25-Feb-2026
• Ref Project: SIST EN ISO 4027:2026 - Fasteners - Hexagon socket set screws with truncated cone point (ISO 4027:2026)

Relations

• Replaces: EN ISO 4027:2003 - Hexagon socket set screws with cone point (ISO 4027:2003)
• Effective Date: 08-Nov-2023
• Refers: ISO 4042:2022 - Fasteners — Electroplated coating systems
• Effective Date: 22-Apr-2026
• Refers: ISO 225:2010 - Fasteners — Bolts, screws, studs and nuts — Symbols and descriptions of dimensions
• Effective Date: 22-Apr-2026
• Refers: ISO 23429:2004 - Gauging of hexagon sockets
• Effective Date: 22-Apr-2026
• Refers: ISO 6157-1:1988 - Fasteners — Surface discontinuities — Part 1: Bolts, screws and studs for general requirements
• Effective Date: 22-Apr-2026
• Refers: ISO 8991:1986 - Designation system for fasteners
• Effective Date: 22-Apr-2026
• Refers: ISO 8992:2005 - Fasteners — General requirements for bolts, screws, studs and nuts
• Effective Date: 22-Apr-2026
• Refers: ISO 4759-1:2000 - Tolerances for fasteners — Part 1: Bolts, screws, studs and nuts — Product grades A, B and C
• Effective Date: 22-Apr-2026
• Refers: ISO 4753:2011 - Fasteners — Ends of parts with external ISO metric thread
• Effective Date: 22-Apr-2026
• Refers: ISO 888:2012 - Fasteners — Bolts, screws and studs — Nominal lengths and thread lengths
• Effective Date: 22-Apr-2026
• Refers: ISO 3506-3:2025 - Fasteners — Mechanical properties of corrosion resistant stainless steel fasteners — Part 3: Set screws (and similar fasteners not under tensile stress) with specified grades and hardness classes
• Effective Date: 22-Apr-2026
• Refers: ISO 965-1:2013 - ISO general purpose metric screw threads — Tolerances — Part 1: Principles and basic data
• Effective Date: 22-Apr-2026
• Refers: ISO 10683:2018 - Fasteners — Non-electrolytically applied zinc flake coating systems
• Effective Date: 22-Apr-2026
• Refers: ISO 3269:2019 - Fasteners — Acceptance inspection
• Effective Date: 22-Apr-2026
• Refers: ISO 898-5:2012 - Mechanical properties of fasteners made of carbon steel and alloy steel — Part 5: Set screws and similar threaded fasteners with specified hardness classes — Coarse thread and fine pitch thread
• Effective Date: 22-Apr-2026

Overview

EN ISO 4027:2026 specifies the characteristics and requirements for hexagon socket set screws with truncated cone point, focusing on metric coarse pitch threads for both steel (M1.6 to M30) and stainless steel (M1.6 to M24) fasteners in product grade A. This standard, developed by CEN and aligned with ISO 4027:2026, establishes technical parameters, dimensional criteria, marking, and labelling requirements for these widely used fastening elements. The scope emphasizes that these set screws are not designed for applications involving tensile loading. Optional mechanical properties, material grades, and dimensions can be selected in reference to other established international standards as needed for specialized use.

Key Topics

• Product Range

  • Metric coarse threads: from M1.6 up to M30 for steel, and up to M24 for stainless steel fasteners.
  • Product grade A for quality assurance and interchangeability.

• Design & Construction

  • Hexagon socket to allow for secure tool engagement.
  • Truncated cone point for precise and reliable location in assembly.
  • Set screws are intended for securing parts together through friction rather than bearing tensile loads.

• Material and Hardness Classes

  • Selection from ISO 898-5 for steel set screws.
  • Selection from ISO 3506-3 for stainless steel grades and hardness classes.
  • Reference to ISO 888, ISO 965-1, or ISO 4753 for alternative dimensions.

• Marking and Labelling

  • No mandatory product marking unless agreed upon.
  • Package labelling must include standard reference, size and length, hardness class or grade, surface condition, manufacturer info, lot number, and quantity.

Applications

Hexagon socket set screws with truncated cone point are essential in a range of mechanical and industrial settings where compact, reliable, and easily adjustable fastening is required. Typical applications include:

• Securing Components on Shafts: Used in gears, pulleys, and collars on rotating shafts to prevent movement or slipping.
• Electrical and Electronic Assemblies: Beneficial in assembling bus bars, circuit elements, or terminal connections.
• Machine Tools and Fixtures: Provide precise clamping without surface marring, useful in jigs and fixtures for repeatable setups.
• General Mechanical Engineering: Ensure components stay in fixed positions during operation where accessible, discreet fastening is important.

Because these set screws are not intended for tensile load applications, they are most suitable where the principal force is lateral or where position retention is critical rather than structural strength.

Related Standards

EN ISO 4027:2026 references and can be used in conjunction with several international fastener standards, enhancing versatility and compliance in different use cases:

• ISO 898-5: Mechanical properties for steel set screws and similar fasteners.
• ISO 3506-3: Mechanical properties and grades for stainless steel set screws.
• ISO 888: Standard for fastener lengths and thread lengths.
• ISO 965-1: Tolerances for ISO metric screw threads.
• ISO 4753: Definitions related to ends of externally threaded parts.
• ISO 8991 / ISO 8992: Designation system and general requirements for fasteners.
• ISO 4042 / ISO 10683: Surface treatment and coating standards for fasteners.
• ISO 4759-1: Product tolerances for screws, bolts, and nuts.
• ISO 6157-1: Requirements for surface discontinuities.
• ISO 3269: Acceptance inspection for fasteners.

By adhering to EN ISO 4027:2026, manufacturers and users ensure compatibility, safety, and performance in global supply chains for mechanical fastening solutions. This standard supports efficient procurement, clear communication, and consistent quality, crucial for industrial assembly, maintenance, and repair operations.

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2026
Vezni elementi - Navojni zatiči z notranjim šestkotnikom in končino s skrajšano
konico (ISO 4027:2026)
Fasteners - Hexagon socket set screws with truncated cone point (ISO 4027:2026)
Verbindungselemente - Gewindestifte mit Innensechskant und abgeflachter Spitze (ISO
4027:2026)
Fixations - Vis sans tête à six pans creux, à bout tronconique (ISO 4027:2026)
Ta slovenski standard je istoveten z: EN ISO 4027:2026
ICS:
21.060.10 Sorniki, vijaki, stebelni vijaki Bolts, screws, studs
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 4027
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2026
EUROPÄISCHE NORM
ICS 21.060.10 Supersedes EN ISO 4027:2003
English Version
Fasteners - Hexagon socket set screws with truncated cone
point (ISO 4027:2026)
Fixations - Vis sans tête à six pans creux, à bout Verbindungselemente - Gewindestifte mit
tronconique (ISO 4027:2026) Innensechskant und abgeflachter Spitze (ISO
4027:2026)
This European Standard was approved by CEN on 22 August 2025.

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
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 4027:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 4027:2026) 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 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 August 2026, and conflicting national standards shall
be withdrawn at the latest by August 2026.
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.
This document supersedes EN ISO 4027:2003.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. 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 4027:2026 has been approved by CEN as EN ISO 4027:2026 without any modification.

International
Standard
ISO 4027
Fourth edition
Fasteners — Hexagon socket set
2026-02
screws with truncated cone point
Fixations — Vis sans tête à six pans creux, à bout tronconique
Reference number
ISO 4027:2026(en) © ISO 2026
ISO 4027:2026(en)
© ISO 2026
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: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 4027:2026(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Dimensions . 2
5 Requirements and reference International Standards . 5
6 Marking and labelling . 6
6.1 Marking on product . .6
6.2 Labelling on package .6
7 Designation . 6
Bibliography . 7

iii
ISO 4027:2026(en)
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,
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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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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, Subcommittee SC 11, Fasteners
with metric external thread, in collaboration with the European Committee for Standardization (CEN)
Technical Committee CEN/TC 185, Fasteners, in accordance with the Agreement on technical cooperation
between ISO and CEN (Vienna Agreement).
This fourth edition cancels and replaces the third edition (ISO 4027:2003), which has been technically
revised.
The main changes are as follows:
— Title and Scope have been changed from “cone point” to “truncated cone point”;
— M30 has been added for steel hexagon socket set screws;
— the determination of d has been defined by formulae and logical tolerance classes accordin
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