Overview
EN ISO 8740:2025 (Fasteners - Parallel grooved pins, with chamfer point - Full-length diamond grooves) defines the characteristics, dimensions and requirements for parallel grooved pins with a chamfer point and full‑length diamond grooves (open ends). The standard covers pins made from steel and stainless steel with nominal diameters from 1 mm to 25 mm and specifies their primary function: locking two or more parts together with easy installation (chamfer point) and high pull‑out resistance due to the pin’s elastic fit.
Key topics and technical requirements
- Scope & function: Pins for mechanical locking and assembly with maximum pull‑out resistance.
- Materials: Steel and stainless steel (stainless grades A2, A4, C1 and F1 are included); other materials allowed by agreement if mechanical/physical properties are met.
- Dimensions & tolerances: Detailed dimension tables for diameters 1–25 mm, length ranges, and requirements for expanded diameter (d) and pin straightness (t). Because grooves run full length, diameter d must be controlled before grooving.
- Ends & geometry: Pins are supplied with a chamfer point for insertion; rounded ends are the default. Chamfer‑end option has been deleted in this edition.
- Mechanical & surface requirements: As‑processed tolerances, hardness and shear resistance follow general requirements in ISO 13669; surface finishes and coatings referenced (ISO 4042, ISO 9717, ISO 10683).
- Quality & inspection: Acceptance inspection per ISO 3269; workmanship must be free of burrs and detrimental defects.
- Labelling & designation: Clause on packaging labelling and standardised designation added to facilitate supply and traceability.
Applications and who uses it
EN ISO 8740:2025 is used by:
- Design and mechanical engineers specifying reliable fastening solutions for assemblies.
- Fastener manufacturers and suppliers for production, quality control and product data sheets.
- Quality assurance and inspection teams implementing acceptance criteria and dimensional checks.
- Purchasing and procurement to ensure ordered components comply with a recognised standard.
Typical uses include any assembly requiring precise, high‑retention pins to lock components together and allow straightforward installation via chamfered insertion.
Related standards
- ISO 13669 - Grooved pins - General requirements (functional principles, hole dimensions, control of expanded diameter and straightness)
- ISO 3269 - Acceptance inspection
- ISO 3506‑6 - Selection of stainless steels for fasteners
- ISO 4042, ISO 9717, ISO 10683 - Coating and surface treatment references
EN ISO 8740:2025 provides clear dimensional, material and inspection guidance for specifying and producing parallel grooved pins with chamfer point and full‑length diamond grooves, improving interchangeability and performance in mechanical assemblies.
