ISO 8743:1997

Overview

ISO 8743:1997 specifies the characteristics of grooved pins - half‑length centre grooved (non‑through grooves). It covers pins with three equally spaced central grooves that extend over half the pin length, intended for a tight interference fit. The standard applies to pins made of mild steel or austenitic stainless steel, in nominal diameters from 1.5 mm to 25 mm.

Keywords: ISO 8743, grooved pins, half-length centre grooved, grooved pin dimensions, grooved pin specification

Key Topics

• Geometry and dimensions: Defines nominal diameters and associated dimensional limits, groove form and extent (centre grooves over half the length), and an allowance for a chamfer. A dimension table and figure are provided for selection of standard sizes.
• Bulged relief (d2): Material displaced by the grooves forms a bulge (diameter d2) larger than the nominal diameter to ensure a tight press fit when installed in a hole of nominal pin diameter.
• Tolerances and fit: Specifies drilling guidance - the hole diameter should equal the pin nominal diameter with tolerance grade H11 to obtain the intended interference fit.
• Materials and hardness: Accepts mild steel and austenitic stainless steel; mechanical/hardness requirements and reference to ISO 3506‑1 for stainless fastener characteristics are included.
• Surface finish and coatings: Preferred finishes include black oxide, phosphate conversion coatings, and zinc plating with chromate (see ISO 9717 and ISO 4042). All tolerances apply before plating.
• Mechanical testing and quality: Shear strength testing is referenced to ISO 8749; reception inspection is covered by ISO 3269. Pins must be free from harmful irregularities.
• Designation examples: Standardized naming format (e.g., “Goupille cannelée ISO 8743 - 6 · 50 - St”) for ordering and documentation.

Applications

• Assembly fastenings requiring a secure, interference fit where rotational or axial movement must be limited.
• Precision mechanical assemblies, tool and die components, and subassemblies in automotive, machinery, and manufacturing equipment.
• Used by: mechanical design engineers, fastener manufacturers, procurement/specification writers, quality/inspection teams, and maintenance engineers.

Related Standards (if applicable)

• ISO 3269 - Fasteners - Acceptance inspection
• ISO 3506‑1 - Mechanical properties of corrosion‑resistant stainless steel fasteners (part 1)
• ISO 4042 - Fasteners - Electroplated coatings
• ISO 8749 - Pins and grooved pins - Shear test
• ISO 9717 - Phosphate conversion coatings - Specification method

This standard is essential when specifying grooved pins with centre grooves over half the length to ensure correct dimensioning, mechanical performance and interchangeability across suppliers.