ISO 2338:1997

Overview

ISO 2338:1997 defines the characteristics and designation of parallel pins (also called cylindrical or straight pins) made from unhardened steel and austenitic stainless steel. The standard covers nominal diameters from 0.6 mm to 50 mm, specifies dimensional tolerances and commercial lengths, and gives requirements for material, surface finish, hardness and workmanship. ISO 2338 is a fasteners standard intended for manufacturers, designers and quality inspectors who need consistent, interchangeable pins for precision assembly and tooling.

Key Topics

• Size range and dimensions: Nominal diameters d = 0.6 mm to 50 mm; standard nominal lengths listed with acceptable min/max tolerances and commercial length steps (above 200 mm in 20 mm increments).
• Tolerance classes: Typical tolerance classes referenced are m6 and h8; tolerances apply before any plating or coating.
• Material and hardness:
  • Unhardened steel (St): hardness specified in the standard (given as HV30 range).
  • Austenitic stainless steel (A1): material grade referred to ISO 3506-1 with its own hardness range.
• Surface finish and coatings:
  • Steel pins: plain (natural) finish or treated finishes such as black oxide, phosphate coating or zinc plating with chromate conversion; pins often supplied with protective lubricant unless otherwise agreed.
  • Austenitic stainless steel: normally supplied plain (natural finish).
• Surface roughness:
  • For m6 tolerance class: R < 0.8 µm
  • For h8 tolerance class: R < 1.6 µm
• Workmanship and acceptability:
  • Pins must be free from irregularities, detrimental defects and burrs.
  • Acceptance inspection follows ISO 3269.

Applications

ISO 2338 parallel pins are widely used for:

• Alignment and location in assemblies (dowels and locating pins)
• Fixtures, jigs and tooling for machining and production
• Precision mechanical assemblies in automotive, machinery, electronics and other industrial equipment
• Replacement parts and procurement where interchangeability and conformity to standards are required

Who uses it:

• Fastener and precision pin manufacturers
• Mechanical designers and engineers specifying dowel/pin dimensions and tolerances
• Procurement and quality control personnel enforcing acceptance inspection criteria

Related Standards

• ISO 3269 - Fasteners: Acceptance inspection
• ISO 3506-1 - Mechanical properties of corrosion‑resistant stainless steel fasteners (referenced for austenitic grades)
• ISO 4042 - Fasteners: Electroplated coatings (referenced)
• ISO 9717 - Phosphate conversion coatings for metals

Designation example from ISO 2338:

• Parallel pin ISO 2338 – 6 m6 × 30 – St (steel)
• Parallel pin ISO 2338 – 6 m6 × 30 – A1 (austenitic stainless steel)

Keywords: ISO 2338, parallel pins, dowel pins, unhardened steel pins, austenitic stainless steel pins, pin dimensions, m6 tolerance, h8 tolerance, fasteners standard.