Overview
EN ISO 8744:2025 - Fasteners: Taper grooved pins with full-length progressive grooves specifies the characteristics of taper grooved pins (closed end at the insertion side) made in steel and stainless steel, with nominal diameters from 1 mm to 25 mm. These taper grooved pins are intended to lock together two or more parts with easy installation and high pull-out resistance thanks to the pin’s elastic-fit behaviour. EN ISO 8744:2025 was prepared by ISO/TC 2 in collaboration with CEN/TC 185 and supersedes EN ISO 8744:1997.
Key topics and technical requirements
- Scope and geometry
- Taper grooved pins with full-length progressive grooves; three grooves that remain closed at the rounded/chamfered insertion end and open at the opposite end.
- Pin end options: rounded (RN) by default; chamfered (CH) by request.
- Dimensions and tolerances
- Nominal diameters: 1 mm to 25 mm; detailed lengths and expanded diameter data are provided in Tables 1 and 2.
- Expanded diameter (d) and pin straightness (t) control requirements reference ISO 13669.
- Tolerances for rounded ends and chamfered ends added in this edition.
- Materials and grades
- Steel (symbol St) and stainless steels, including added grades A2, A4, C1, F1.
- Other materials (hardened steels, brass, aluminium) allowed by agreement with manufacturer.
- Mechanical and inspection requirements
- Mechanical, physical and inspection requirements are linked to ISO 13669 and other referenced standards; coatings and surface treatments follow ISO 4042, ISO 10683, ISO 9717 where applicable.
- Labelling and designation
- Packaging and labelling specifications are added (Clause 8) to support traceability and procurement.
Applications
- Primary function: locking and locating components in assemblies where a secure press-fit and resistance to pull-out are required.
- Typical application areas include mechanical assemblies, general machinery, tooling, and any engineering context requiring simple installation combined with high retention.
- The tapered, grooved design is suited where elastic deformation of the pin improves joint reliability.
Who uses this standard
- Fastener manufacturers and product designers specifying taper grooved pins
- Procurement and quality assurance teams verifying conformance to EN ISO 8744:2025
- Mechanical, design and assembly engineers requiring dimensional, material and inspection guidance
- Test and inspection laboratories applying acceptance criteria
Related standards
EN ISO 8744:2025 provides the dimensional, material and inspection framework engineers and manufacturers need for consistent, reliable use of taper grooved pins across industries.
