Overview
EN ISO 8746:2025 / ISO 8746:2025 specifies the characteristics of grooved pins with round head and full‑length diamond grooves (nominal diameters 2 mm to 20 mm). It covers pins with a pilot point (PL) or optional chamfered point (CH) in steel and stainless steel, intended primarily for locking together two or more parts. These pins are designed for easy installation (pilot/chamfer point) and high pull‑out resistance due to the pin’s elastic fit behaviour. General functional principles and assembly requirements are referenced to ISO 13669. This edition (third) supersedes EN ISO 8746:1997 and was adopted by CEN in 2025.
Key topics and technical requirements
- Scope and intent: Grooved pins with round head, full‑length diamond grooves, nominal diameters 2–20 mm, materials steel and specified stainless grades.
- Geometry and grooves:
- Three diamond grooves (120° apart ±20°); groove angle 70° (reference per ISO 13669).
- Grooves closed at the pilot point and open at a chamfer point.
- Head diameters and underhead dimensions specified; maximum distance from underhead bearing surface to groove start defined.
- Points and symbols:
- Pilot point symbol PL (default) and chamfer point CH (on request); point lengths specified as minimums.
- Dimensions and tolerances:
- Detailed size tables for diameters 2–20 mm and standard length ranges; tolerances for expanded diameter and pin straightness controlled per ISO 13669.
- Materials and finishes:
- Steel (St) and stainless grades (A1, A2, A4, C1, F1) specified; other materials possible by agreement with purchaser.
- Coating and surface treatments referenced to ISO 4042 (electroplating), ISO 10683 (zinc flake), ISO 9717 (phosphate), with workmanship requirements (free of burrs, defects).
- Inspection and labelling:
- Acceptance inspection per ISO 3269; package labelling must include reference to ISO 8746, nominal diameter and length, CH option if applicable, and material symbol (e.g., St).
Applications - who uses this standard
- Design and manufacturing engineers specifying locking pins in mechanical assemblies.
- Fastener manufacturers producing grooved pins to standardized dimensions and finishes.
- Procurement and quality inspectors checking conformity, labelling and acceptance criteria.
- Typical applications include mechanical assemblies where reliable, easy-to-install locking elements with high pull‑out resistance are required (general manufacturing, machinery, automotive and equipment assemblies).
Related standards
Keywords: EN ISO 8746, ISO 8746:2025, grooved pins, round head, diamond grooves, pilot point, chamfer point, fasteners, steel, stainless steel, pull‑out resistance, ISO 13669.
