ISO 23886-2021 PDF

Full title and description

Aerospace — Collar, threaded, self-locking — Test method for torque and preload. This International Standard defines a laboratory test method to determine the torque characteristics and preload of threaded, self‑locking collars used in aerospace applications, including locking torque, breakaway torque, torque‑off and the preload achieved when installed under specified conditions.

Abstract

This document describes a torque and preload test method for threaded collars. It specifies how to measure locking torque, breakaway torque, torque‑off and the preload of threaded, self‑locking collars to support consistent verification and reporting of fastening performance in aerospace systems.

General information

• Status: Published.
• Publication date: 21 July 2021 (Edition 1, 2021).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 49.030.99 (fasteners and related components).
• Edition / version: Edition 1 (2021).
• Number of pages: 5.

Scope

ISO 23886:2021 specifies a laboratory test method for measuring torque and preload parameters of threaded, self‑locking collars used in aerospace assemblies. The procedure applies to the determination of locking torque, breakaway torque (after the collar has been subjected to service or test conditions), torque‑off (torque required to remove the collar) and the axial preload produced when the collar is installed under defined conditions. The standard is intended for use where consistent, repeatable test results are required for design verification, quality control and supplier acceptance testing.

Key topics and requirements

• Definitions and terms relevant to threaded, self‑locking collars and torque/preload measurements.
• Specification of test specimens, preparation and environmental/conditioning requirements prior to testing.
• Required test apparatus and instrumentation for accurate torque and preload measurement.
• Step‑by‑step test procedures for measuring locking torque, breakaway torque, torque‑off and preload.
• Data recording, calculation of results and reporting formats to ensure repeatability and traceability of test outcomes.
• Acceptance and interpretation guidance for test results (for use in procurement, QA and design validation).

(Summary based on the standard’s documented scope and abstract.)

Typical use and users

Typical users of ISO 23886:2021 include aerospace OEMs and suppliers, fastener and insert manufacturers, test and calibration laboratories, quality assurance and inspection teams, design engineers specifying fastening solutions, and procurement specialists who need objective verification of locking and preload performance. The standard is used during product development, incoming inspection, acceptance testing and failure investigation.

Related standards

ISO 23886:2021 is produced under ISO/TC 20/SC 4 (Aerospace fastener systems) and sits alongside related aerospace fastener test and product standards — for example ISO 23887:2021 (blind fasteners, threaded type, self‑locking — test method for locking torque) and earlier/related documents on self‑locking inserts and aerospace fastening components (e.g., ISO 13596 series on self‑locking inserts). These related items are part of the TC20/SC4 work programme addressing fastening hardware and test methods.

Keywords

collar; threaded collar; self-locking; torque test; preload; locking torque; breakaway torque; torque‑off; aerospace fasteners; test method; ISO 23886:2021.

FAQ

Q: What is this standard?

A: ISO 23886:2021 is an International Standard that specifies a laboratory test method to measure torque and preload characteristics of threaded, self‑locking collars used in aerospace applications.

Q: What does it cover?

A: It covers the test procedures, apparatus, specimen preparation and reporting required to determine locking torque, breakaway torque, torque‑off and axial preload for threaded, self‑locking collars. The goal is consistent, repeatable measurement for design verification and quality control.

Q: Who typically uses it?

A: Aerospace OEMs and suppliers, fastener manufacturers, independent test laboratories, QA/inspection teams and design engineers who need verified torque/preload performance data for procurement, acceptance testing and engineering validation.

Q: Is it current or superseded?

A: As published on 21 July 2021, ISO 23886:2021 is the current (first) edition and its status is Published. Users should check the ISO catalogue or national standards bodies for any subsequent amendments or withdrawal notices.

Q: Is it part of a series?

A: It is part of the portfolio of aerospace fastener standards developed by ISO/TC 20/SC 4 and is related to other test methods and product standards for self‑locking and blind fasteners (for example ISO 23887:2021) and standards on inserts and fastener dimensions.

Q: What are the key keywords?

A: Collar, threaded collar, self‑locking, torque, preload, locking torque, breakaway torque, torque‑off, aerospace fasteners, test method, ISO 23886.