ISO 8745:2025

Overview

ISO 8745:2025 - Fasteners - Taper grooved pins - Half-length progressive grooves specifies the characteristics, dimensions and marking of taper grooved pins with half‑length progressive grooves (close‑end at the insertion side). The standard covers pins manufactured in steel and stainless steel, with nominal diameters from 1 mm to 25 mm, intended for positioning/guiding and enabling relative rotation of assembled parts. General functional requirements and assembly principles are referenced to ISO 13669.

Keywords: ISO 8745:2025, taper grooved pins, half-length progressive grooves, fasteners, steel, stainless steel, expanded diameter.

Key topics and requirements

• Scope and function: Pins designed for easy installation and medium pull‑out resistance due to elastic fit; primary functions are positioning/guiding and permitting relative rotation.
• Materials: Steel (symbol St) and stainless steel grades (A1, A2, A4, C1, F1); other materials (e.g., hardened steels, brass, aluminium) allowed by agreement when mechanical/physical properties are defined.
• Dimensions and geometry:
  • Nominal diameter range: 1 mm to 25 mm.
  • Grooves: three grooves, open at the non‑insertion end; groove spacing angle 120° ±20°; groove angle ~70° (reference).
  • Groove length equals l/2 with tolerances:
    • l ≤ 10 mm: ±0.3 mm
    • 10 mm < l ≤ 50 mm: ±0.6 mm
    • 50 mm < l ≤ 100 mm: ±1.0 mm
    • 100 mm < l ≤ 200 mm: ±1.5 mm
  • Expanded diameter (d) and axial straightness (t) are controlled per ISO 13669.
  • End types: rounded (RN) by default; chamfered (CH) optional.
• Surface condition and coatings: As‑processed, clean and bright, electroplated coatings (ISO 4042), zinc‑flake (ISO 10683), phosphate conversion (ISO 9717), passivation options for stainless steel.
• Quality and inspection: Acceptance inspection per ISO 3269; packaging labelling requirements (reference ISO 8745, size, material, finish, lot number, quantity).

Applications and who uses this standard

• Typical users: fastener manufacturers, mechanical design engineers, procurement specialists, quality/inspection teams, and assembly engineers.
• Typical applications: precision positioning and alignment in automotive, aerospace, industrial machinery, tooling, and electronics assemblies where controlled fit and relative rotation are needed.
• Benefits: consistent interchangeability, predictable installation behaviour, standardized labelling and designation for supply chain and quality control.

Related standards

• ISO 13669 - Grooved pins - General requirements (functional principles, inspection)
• ISO 3506-6 - Stainless steel fastener selection
• ISO 4042, ISO 9717, ISO 10683 - Coating/finish specifications
• ISO 3269, ISO 1891-4 - Inspection, acceptance and labelling
• Related grooved-pin product standards: ISO 8739, ISO 8744, ISO 8746, ISO 13670, ISO 13672

Designation example: Grooved pin ISO 8745 – 6 × 50 – RN – St (6 mm × 50 mm, rounded ends, steel).