Overview
ISO 8735:1997 specifies requirements for parallel (cylindrical) pins with internal thread, made of hardened steel and martensitic stainless steel. The standard covers nominal diameters from 6 mm to 50 mm and defines two main types: Type A (through‑hardened, with crown) and Type B (flat, case‑hardened). It provides dimensions, material and hardness requirements, surface finish and quality criteria, and example designation formats.
Key topics and technical requirements
- Diameter and length range: nominal diameters d = 6–50 mm; common nominal lengths listed (16 mm up to 200 mm and beyond in 20 mm steps).
- Types:
- Type A: pins through‑hardened (also available in martensitic stainless steel C1).
- Type B: case‑hardened (cemented) steel pins.
- Materials and composition: the standard gives compositional limits for the steels and the martensitic stainless variant (C1) and permits other materials by agreement.
- Hardness:
- Through‑hardened pins: specified bulk and surface hardness ranges (e.g., 550–650 HV30 surface range referenced in the standard).
- Case‑hardened pins: surface hardness and case depth requirements (minimum case hardness and typical case thickness specified).
- Thread and tolerances: internal threads follow metric ISO tolerances (metric threads, tolerance grade 6H per ISO 965‑2). Thread pitches and matching nominal thread sizes (M4–M24 depending on pin diameter) are listed.
- Surface quality and finish: surface roughness and absence of harmful defects required; coatings are permitted but must address hydrogen embrittlement risks and follow suitable post‑treatment (see ISO 4042).
- Inspection and acceptance: reception and inspection procedures reference ISO 3269.
- Designation examples: e.g., “Goupille cylindrique ISO 8735 – 6·30 – A – St” (hardened steel, 6×30 mm, Type A) or “Goupille cylindrique ISO 8735 – 6·30 – C1” (martensitic stainless C1).
Applications and users
- Typical applications: precise locating, alignment and load‑bearing dowel/pin applications in machinery, tooling, automotive assemblies, and precision equipment where controlled fit, strength and corrosion resistance are required.
- Who uses this standard:
- Mechanical designers and engineers specifying pins for assemblies
- Fastener and component manufacturers producing to ISO dimensions and hardness
- Quality assurance and inspection teams verifying acceptance criteria
- Procurement and supply chain professionals sourcing standardized pins
Related standards
- ISO 965‑2 - metric thread tolerances (6H)
- ISO 3269 - fasteners - acceptance inspection
- ISO 3506‑1 - mechanical properties of corrosion‑resistant stainless fasteners (reference for C1)
- ISO 4042 - electroplated coatings and hydrogen embrittlement precautions
Keywords: ISO 8735, parallel pins, parallel pins with internal thread, cylindrical pins, hardened steel pins, martensitic stainless steel, dowel pins, fastener standard, pin dimensions, thread tolerances.
Open preview (PDF)Parallel pins with internal thread, of hardened steel and martensitic stainless steel