ISO 10511-2025 PDF

Full title and description

ISO 10511:2025 — Fasteners — Prevailing torque hexagon nuts — Thin nuts (with non‑metallic insert). This International Standard specifies the characteristics, dimensions and requirements for prevailing‑torque (self‑locking) hexagon thin nuts incorporating a non‑metallic insert, for steel and stainless‑steel grades, covering metric coarse pitch threads from M3 to M39 and product grades A and B.

Abstract

ISO 10511:2025 defines the dimensional, material and performance features of prevailing‑torque hexagon thin nuts with non‑metallic inserts (commonly known as nylon‑insert or similar self‑locking thin nuts). It gives nominal dimensions, the height relationship to established nut styles, and requirements for the prevailing‑torque feature across sizes M3 to M39. Notes and annexes address small‑diameter design details and warn that thin nuts (style 0) have reduced loadability and are not intended to resist thread stripping; where different material or property class choices are required, ISO 3506‑2 and ISO 898‑2 are referenced.

General information

• Status: Published
• Publication date: 13 June 2025
• Publisher: International Organization for Standardization (ISO)
• ICS / categories: 21.060.20 (Fasteners)
• Edition / version: 3rd edition (2025)
• Number of pages: 9

Scope

This standard specifies the characteristics of prevailing‑torque hexagon thin nuts (with non‑metallic insert) in steel and stainless steel, for metric coarse pitch threads M3 to M39, and product grades A and B. It covers geometric dimensions, the design and height of the prevailing‑torque feature relative to established nut heights, and limits, plus specific provisions for sizes below M5. The standard is restricted to thin (style 0) hexagon nuts with integrated non‑metallic inserts and does not substitute requirements for regular or high nuts where different load performance is required.

Key topics and requirements

• Definition and designation of prevailing‑torque hexagon thin nuts with non‑metallic insert (self‑locking feature).
• Dimensional requirements for thread sizes M3 to M39, including overall height and prevailing‑torque feature height relative to m_min/m_max conventions.
• Material scope: steel and stainless‑steel grades with guidance to select specific property classes from ISO 3506‑2 where needed.
• Performance notes and warnings: reduced loadability of thin (style 0) nuts and unsuitability for resisting thread stripping (reference to ISO 898‑2).
• Product grades and markings: product grade designations (A and B) and related identification practices.
• Annex provisions for nuts with D < M5 and specific small‑diameter design principles.

Typical use and users

Used by fastener manufacturers, mechanical and design engineers, quality and procurement teams, and testing laboratories involved in the selection, specification and verification of self‑locking thin nuts for machinery, automotive, electronics enclosures, and other assemblies where space or reduced nut height is required but a prevailing‑torque locking feature is desired.

Related standards

Commonly referenced standards include ISO 898‑2 (mechanical properties of fasteners — nuts), ISO 4035 (hexagon nuts, thin style dimensions), ISO 3506‑2 (stainless steel fasteners — mechanical properties), and regional/adopted equivalents such as EN ISO 10511 and national standards derived from ISO 10511. Earlier edition: ISO 10511:2012 (withdrawn/superseded by 2025 edition).

Keywords

ISO 10511, prevailing torque, self‑locking, hexagon thin nut, non‑metallic insert, nylon insert, thin nuts, style 0, fasteners, M3–M39, product grade A, product grade B.

FAQ

Q: What is this standard?

A: ISO 10511:2025 is an International Standard that specifies the characteristics and dimensional/performance requirements for prevailing‑torque hexagon thin nuts incorporating a non‑metallic insert.

Q: What does it cover?

A: It covers geometry, heights, thread sizes (M3–M39), material scope (steel and stainless steel), product grades (A and B), and specific provisions for small diameters and the prevailing‑torque feature; it also references related mechanical property standards.

Q: Who typically uses it?

A: Fastener manufacturers, product designers, mechanical engineers, purchasing and quality teams, and test laboratories that specify, produce or verify self‑locking thin nuts for use in confined assemblies and applications requiring a locking feature.

Q: Is it current or superseded?

A: The 2025 edition is the current published edition, superseding the 2012 edition of ISO 10511.

Q: Is it part of a series?

A: ISO 10511 is part of the family of ISO standards covering fasteners and nut/bolt properties and dimensions; it works alongside standards such as ISO 898‑2, ISO 4035 and ISO 3506‑2 and may be adopted as EN ISO or national equivalents.

Q: What are the key keywords?

A: Prevailing torque, self‑locking, hexagon thin nut, non‑metallic insert, nylon insert, fasteners, ISO 10511:2025, M3–M39, product grades A/B.