ISO 6362-4:2022

Overview

ISO 6362-4:2022 - "Wrought aluminium and aluminium alloys - Extruded rods/bars, tubes and profiles - Part 4: Tolerances on form and dimensions for profiles" - defines the permissible dimensions and geometric form tolerances for extruded aluminium profiles whose cross-section fits within a circumscribing circle up to 800 mm. It applies to extruded profiles for general engineering applications and complements other parts of the ISO 6362 series (notably ISO 6362-1 and ISO 6362-7).

Key topics and technical requirements

• Scope limits: Profiles with a circumscribing circle ≤ 800 mm; general engineering use only.
• Dimensional tolerances: Tables (ordinary and special classes) provide tolerances by nominal section sizes, alloy group and feature type. Tolerance values vary with:
  • cross‑section size (A, D etc.),
  • whether the profile is solid or hollow,
  • alloy group (Group I and Group II as listed in ISO 6362-7),
  • and the local geometry (e.g., thin walls, openings).
• Tolerances on form: Requirements and definitions for:
  • Straightness
  • Convexity / concavity
  • Curved cross-section or contour
  • Twist
  • Angularity
  • Corner and fillet radii
• Length and end conditions: Rules for acceptable lengths and squareness of cut ends.
• Special cases & purchaser-supplier agreement:
  • When wall-thickness ratios, hollow-space percentages or angled features occur, tolerances can require mutual agreement.
  • Purchaser must specify whether ordinary or special tolerances are required and whether outside or inside dimensions are to be controlled.

Practical applications - who uses ISO 6362-4

• Extrusion mills and manufacturers - to set production tolerances and quality targets for extruded aluminium profiles.
• Design and mechanical engineers - to specify realistic tolerances during product design and ensure interchangeability.
• Purchasers and procurement teams - to define inspection and delivery conditions in contracts (ordinary vs special class).
• Quality managers and inspection labs - to verify conformity against the standard’s tolerance tables and form criteria.
• Fabricators and assemblers - to anticipate fit, function and machining allowances when using extruded profiles.

Related standards and references

• ISO 6362 series - other parts cover inspection/delivery (ISO 6362-1) and alloy listings (ISO 6362-7).
• The standard references the ISO/IEC Directives for development and maintenance.

Keywords: ISO 6362-4, aluminium extruded profiles tolerances, tolerances on form and dimensions, wrought aluminium, extrusion tolerances, aluminium alloys, profile tolerances.