ISO 8752:2009

Overview

ISO 8752:2009 specifies the characteristics of slotted spring‑type straight pins - heavy duty. It covers pins made of steel or austenitic/martensitic stainless steel with nominal diameters from 1 mm to 50 mm inclusive. The standard defines dimensional series, material and hardness requirements, surface finish guidance, mechanical tests and designation formats to ensure interchangeability and reliable performance in press‑fit applications.

Key topics and requirements

• Scope and sizes: Heavy‑duty slotted spring pins, nominal diameters d = 1 mm to 50 mm; standardized nominal lengths and dimensional limits are given in tables.
• Hole tolerance and fit: The mating hole diameter shall equal the pin nominal diameter and conform to tolerance class H12. The slot must not fully close when mounted in the smallest permitted hole.
• Materials and heat treatment:
  • Permitted materials: plain carbon steel, silicon‑manganese steel, martensitic and austenitic stainless steel (with chemical composition limits shown in the standard).
  • Hardened and tempered or austempered conditions are specified with Vickers hardness ranges; hardness testing follows ISO 6507‑1.
• Mechanical performance:
  • Shear strength tests are required in accordance with ISO 8749. Minimum double shear strength values are specified for steel and martensitic stainless steel (austenitic stainless pins have no specified double shear values).
  • Acceptance inspection follows ISO 3269.
• Slot types and workmanship:
  • Standard slotted form; non‑interlocking (slot type N) pins may be supplied by agreement.
  • Pins must be free of burrs and defects.
• Surface finish and corrosion protection:
  • Default: plain finish with protective lubricant.
  • If coating/plating is used, processes should avoid hydrogen embrittlement; electroplating or phosphate coating require immediate baking per ISO 4042 recommendations.

Applications and users

ISO 8752:2009 is used where robust, removable or self‑retaining fasteners are required:

• Typical users: fastener manufacturers, mechanical design engineers, quality and procurement teams, OEMs in automotive, industrial machinery, agricultural equipment, and construction tools.
• Applications: locating, pivot, retaining and shear‑sacrificial connections in assemblies that require standardized spring pins / slotted pins with predictable press‑fit performance and shear capacity.

Related standards

• ISO 3269 - Fasteners: acceptance inspection
• ISO 4042 - Fasteners: electroplated coatings (hydrogen embrittlement guidance)
• ISO 6507‑1 - Vickers hardness test method
• ISO 8749 - Pins and grooved pins: shear test
• ISO 13337 - Spring‑type straight pins - Slotted, light duty

Keywords: ISO 8752:2009, spring‑type straight pins, slotted heavy duty, slotted pins, spring pins, fastener standards, shear strength, Vickers hardness, H12 tolerance, hydrogen embrittlement.