ISO 8739:2025

Overview

ISO 8739:2025 specifies requirements for parallel grooved pins with pilot point and full‑length diamond grooves (closed‑end at the insertion side) manufactured in steel and stainless steel. It covers nominal diameters from 1 mm to 25 mm and defines the pin form intended for locking together two or more parts with easy installation (pilot point) and high pull‑out resistance (elastic fit). General functional principles and assembly requirements are covered by the companion reference standard ISO 13669.

Key topics and technical requirements

• Scope and function: Pins designed for locking, alignment and high pull‑out resistance using elastic interference fit.
• Geometry and dimensions: Detailed dimension tables and figures for nominal diameters 1–25 mm, standard length ranges, and groove geometry (three diamond grooves, 120° spacing).
• Pilot point and ends: Pilot point for easy insertion; default rounded ends (RN), chamfered ends (CH) available on request.
• Control of key parameters: Expanded diameter (d) and pin straightness (t) tolerances are specified and controlled per ISO 13669.
• Materials and grades: Steel and stainless steel options; stainless grades A2, A4, C1 and F1 added. Other materials (hardened steels, brass, aluminium) can be agreed between purchaser and manufacturer.
• Surface conditions and coatings: As‑processed, clean and bright, electroplated coatings (ISO 4042), phosphate conversion (ISO 9717), and zinc‑flake systems (ISO 10683) are referenced.
• Inspection and acceptance: Acceptance inspection per ISO 3269; labelling and lot identification per ISO 1891‑4.
• Labelling and designation: Required package labelling (reference standard, diameter/length, material, finish, lot number, quantity) and standard designation formats are provided.

Applications and users

ISO 8739:2025 is relevant to:

• Fastener manufacturers and suppliers specifying production tolerances and finishes.
• Design and mechanical engineers selecting pins for assemblies requiring high pull‑out resistance and simple press‑fit installation (automotive, machinery, electrical enclosures, consumer products).
• Quality, procurement and inspection teams ensuring compliance with dimensional, material and labelling requirements.
• OEMs and contract manufacturers integrating dowel‑type locking pins where repeatable alignment and retention are critical.

Practical uses include locking two or more components together, alignment during assembly, and applications where a robust elastic interference fit provides superior pull‑out resistance compared with smooth dowels.

Related standards

• ISO 13669 - Grooved pins - General requirements (functional principles, assembly, control of expanded diameter and straightness)
• ISO 3506‑6, ISO 4042, ISO 9717, ISO 10683 - Material and coating/finish references
• ISO 3269, ISO 1891‑4 - Inspection and labelling/lot identification

Keywords: ISO 8739:2025, parallel grooved pins, pilot point, full‑length diamond grooves, fasteners, pull‑out resistance, pin dimensions, stainless steel fasteners, grooved pins.