Overview
EN ISO 8747:2025 - Fasteners: Grooved pins with countersunk head - Full‑length diamond grooves (ISO 8747:2025)
This standard, adopted by CEN and published in 2025, specifies the characteristics, dimensions and requirements for grooved pins with countersunk head and full‑length diamond grooves with either a pilot point or chamfer point. It covers pins manufactured in steel and stainless steel (nominal diameters 2 mm to 20 mm) intended to lock two or more parts with easy installation and high pull‑out resistance through elastic fit behaviour.
Key Topics
- Scope and function: Pins for locking components; pilot/chamfer point for easy insertion; full‑length diamond grooves for maximal pull‑out resistance.
- Dimensions and tolerances: Detailed dimensional tables and figures for sizes 2–20 mm (head diameter, head height, length, groove geometry). Head diameters have been recalculated and rounded (notably for sizes ≤8 mm and for 16/20 mm).
- Groove geometry: Three grooves (120° spacing ±20°); groove angle of 70° given as a reference; grooves closed at the pilot point, open at the chamfer point.
- Material and finishes: Steel and stainless‑steel grades (A2, A4, C1, F1) specified; other materials may be agreed by purchaser and supplier. Surface treatments and coatings referenced (electroplated, zinc flake, phosphate, passivation).
- Functional/inspection requirements: Control of expanded diameter (d) and pin straightness, workmanship (free of burrs), and acceptance inspection per referenced ISO documents.
- Packaging and labelling: Requirements for labelling and designation to support procurement and traceability.
Applications
Who uses EN ISO 8747:2025 and why:
- Design engineers and product developers selecting fasteners for mechanical assemblies that require secure locking with minimal assembly effort.
- Fastener manufacturers producing grooved pins to meet consistent interchangeability, dimensional accuracy and mechanical performance.
- Procurement and quality engineers ensuring purchased pins conform to specified dimensions, materials and coatings.
- Assembly and maintenance teams that rely on predictable installation behaviour (pilot/chamfer points) and high pull‑out resistance in production or repair.
Practical applications include mechanical fastening in automotive, industrial machinery, electronics enclosures, and any application where press‑fit locking pins with a flush countersunk head are required.
Related Standards
Key referenced standards for requirements and testing:
For procurement and specification, refer to EN ISO 8747:2025 alongside ISO 13669 for general grooved pin principles and assembly requirements.
