ISO 7043:2012
(Main)Prevailing torque type hexagon nuts with flange (with non-metallic insert), style 2 - Product grades A and B
Prevailing torque type hexagon nuts with flange (with non-metallic insert), style 2 - Product grades A and B
ISO 7043:2012 specifies the characteristics of prevailing torque type hexagon nuts with flange (with non-metallic insert), of style 2, with threads from M5 to M20 inclusive, in product grade A for threads up to and including M16 and product grade B for threads above M16, and with property classes 8, 9 and 10.
Écrous hexagonaux à embase, autofreinés (à anneau non métallique), style 2 — Grades A et B
General Information
- Status
- Published
- Publication Date
- 16-Aug-2012
- Technical Committee
- ISO/TC 2/SC 12 - Fasteners with metric internal thread
- Drafting Committee
- ISO/TC 2/SC 12 - Fasteners with metric internal thread
- Current Stage
- 9093 - International Standard confirmed
- Start Date
- 01-Jul-2022
- Completion Date
- 13-Dec-2025
Relations
- Effective Date
- 16-Feb-2012
Overview
ISO 7043:2012 specifies the characteristics of prevailing torque type hexagon nuts with flange (with non‑metallic insert), style 2, for metric threads M5 to M20. It covers dimensional limits, product grades (A for D ≤ M16, B for D > M16), and property classes 8, 9 and 10. The standard defines how these self‑locking flange nuts (with a non‑metallic insert such as polyamide) should be produced and inspected to ensure fit, function and compatibility with metric threaded fasteners.
Key topics and technical requirements
- Scope and thread range: Threads M5–M20 inclusive; product grade A (up to M16) and B (above M16); property classes 8, 9, 10.
- Dimensions: Nut geometry is based on ISO 4161 (hexagon nuts with flange, style 2) with added prevailing‑torque features; detailed dimensional tables (e.g., flats, wrenching height, flange thickness) are provided.
- Materials and insert: Nut body - steel; insert example - polyamide (non‑metallic). Specific materials/coatings must meet referenced standards.
- Threads and tolerances: Tolerance class 6H for internal threads; general thread forms per ISO 261/ISO 724 and limits per ISO 965‑2.
- Mechanical and performance properties: Referenced to ISO 898‑2 and ISO 2320 for mechanical characteristics and prevailing torque behavior.
- Surface finish and coatings: Electroplated coatings per ISO 4042; non‑electrolytically applied zinc‑flake coatings per ISO 10683; other finishes by agreement.
- Quality and acceptability: Surface discontinuities per ISO 6157‑2; acceptance inspection per ISO 3269.
- Gauging: Annex A describes practical gauging using three ring/feeler gauges (A, B, C) to verify hexagon height, wrenching height, corner fill and flange thickness.
Applications and who uses it
ISO 7043:2012 is used by:
- Manufacturers of self‑locking flange nuts to design and produce prevailing torque hexagon nuts that meet international tolerances and performance classes.
- Procurement and quality engineers specifying fasteners for assemblies requiring vibration‑resistant locking behavior (automotive, machinery, construction, and general engineering).
- Test and inspection labs performing dimensional gauging and acceptance inspection of locking nuts.
- Designers and maintenance engineers selecting compliant fasteners for safety‑critical joints where consistent locking torque is required.
Related standards
- ISO 4161 - Hexagon nuts with flange, style 2 (dimensions)
- ISO 261, ISO 724, ISO 965‑2 - Metric threads and tolerances
- ISO 898‑2, ISO 2320 - Mechanical and prevailing torque properties
- ISO 4759‑1 - Tolerances for fasteners (product grades)
- ISO 3269, ISO 4042, ISO 10683, ISO 6157‑2 - Inspection, coatings and surface requirements
Keywords: ISO 7043:2012, prevailing torque hexagon nuts, hexagon nuts with flange, non‑metallic insert, product grade A, product grade B, M5 to M20, property class 8 9 10, fastening standard, fastener gauging.
Frequently Asked Questions
ISO 7043:2012 is a standard published by the International Organization for Standardization (ISO). Its full title is "Prevailing torque type hexagon nuts with flange (with non-metallic insert), style 2 - Product grades A and B". This standard covers: ISO 7043:2012 specifies the characteristics of prevailing torque type hexagon nuts with flange (with non-metallic insert), of style 2, with threads from M5 to M20 inclusive, in product grade A for threads up to and including M16 and product grade B for threads above M16, and with property classes 8, 9 and 10.
ISO 7043:2012 specifies the characteristics of prevailing torque type hexagon nuts with flange (with non-metallic insert), of style 2, with threads from M5 to M20 inclusive, in product grade A for threads up to and including M16 and product grade B for threads above M16, and with property classes 8, 9 and 10.
ISO 7043:2012 is classified under the following ICS (International Classification for Standards) categories: 21.060.20 - Nuts. The ICS classification helps identify the subject area and facilitates finding related standards.
ISO 7043:2012 has the following relationships with other standards: It is inter standard links to ISO 7043:1997. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
You can purchase ISO 7043:2012 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of ISO standards.
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 7043
Third edition
2012-09-01
Prevailing torque type hexagon nuts with
flange (with non-metallic insert), style
2 — Product grades A and B
Écrous hexagonaux à embase, autofreinés (à anneau non métallique),
style 2 — Grades A et B
Reference number
©
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
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Tel. + 41 22 749 01 11
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Published in Switzerland
ii © ISO 2012 – All rights reserved
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Dimensions . 1
4 Requirements and reference International Standards . 4
5 Designation . 4
Annex A (informative) Gauging of hexagon nuts with flange . 5
Bibliography . 7
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 7043 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 7043:1997), of which it constitutes a minor revision.
iv © ISO 2012 – All rights reserved
INTERNATIONAL STANDARD ISO 7043:2012(E)
Prevailing torque type hexagon nuts with flange (with non-
metallic insert), style 2 — Product grades A and B
1 Scope
This International Standard specifies the characteristics of prevailing torque type hexagon nuts with flange
(with non-metallic insert), of style 2, with threads from M5 to M20 inclusive, in product grade A for threads up to
and including M16 and product grade B for threads above M16, and with property classes 8, 9 and 10.
NOTE The dimensions of the nuts correspond to those given in ISO 4161 plus prevailing torque feature.
If other specifications are required, they can be selected from existing International Standards, for example
ISO 261, ISO 724, ISO 898-2, ISO 965-2, ISO 2320 and ISO 4759-1.
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 225, Fasteners — Bolts, screws, studs and nuts — Symbols and descriptions of dimensions
ISO 261, ISO general purpose metric screw threads — General plan
ISO 724, ISO general-purpose metric screw threads — Basic dimensions
ISO 898-2, 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 965-2, ISO general purpose metric screw threads — Tolerances — Part 2: Limits of sizes for general
purpose external and internal screw threads — Med
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