Overview
ISO 6362-5:2022 - "Wrought aluminium and aluminium alloys - Extruded rods/bars, tubes and profiles - Part 5" - defines tolerances on form and dimensions for extruded round, square and hexagonal aluminium bars. It applies to round bars with diameters from 8 mm to 350 mm and square/hexagonal bars with widths across flats from 10 mm to 220 mm. The standard specifies dimensional limits, shape tolerances and measurement methods to ensure consistent quality for extruded aluminium products.
Key topics and technical requirements
- Dimensional tolerances: Diameter and width-across-flats tolerances are tabulated (Table 3) and vary by size and alloy group (Group I and Group II). Example ranges include ±0.22 mm for small Group I bars (8–18 mm) up to ±3.00 mm for large Group II round bars (320–350 mm).
- Alloy grouping: Alloys commonly used are classified into Group I and Group II (Tables 1–2) to reflect manufacturing difficulty and tolerance assignment.
- Circularity: For round bars, circularity is measured as the difference between maximum and minimum diameters in a cross-section and is included within the diameter tolerance.
- Corner radii: Maximum corner radii for square and hexagonal bars are specified (Table 4) according to width across flats.
- Fixed-length and squareness tolerances: Fixed-length tolerances and squareness of cut ends are given (Table 5); squareness tolerances are limited to half the fixed-length tolerance range.
- Form tolerances: Straightness (Table 6), convexity/concavity, twist (Table 7) and squareness for square bars (Table 8) are defined. Measurements are taken with the bar supported on a horizontal base plate to minimize deviation. Note: form tolerances do not apply to tempers H111, H112, O and TX510 (Clause 6.1).
- Measurement guidance: The standard includes measurement positions and diagrams for straightness, twist and squareness to ensure repeatable inspection.
Applications and who uses this standard
ISO 6362-5 is essential for:
- Aluminium extruders and mills specifying and supplying extruded bars.
- Quality assurance and inspection teams performing dimensional and form checks.
- Product designers and mechanical engineers who need guaranteed tolerances for fit, assembly and machining.
- Buyers and procurement professionals creating technical purchase specifications for aluminium stock.
- Industries using extruded bars in construction, automotive components, architectural profiles, and machining stock.
Using this standard helps reduce rejects, ensure interchangeability, and streamline supplier–customer technical communication.
Related standards
- ISO 6362-1 - Technical conditions for inspection and delivery (referenced normative).
- ISO 6362-7 - Chemical composition of wrought aluminium alloys (alloys listed).
- The document also cross-references industry alloy designation resources (Aluminum Association “Teal sheets”).
Keywords: ISO 6362-5, tolerances, wrought aluminium, extruded bars, round bars, square bars, hexagonal bars, dimensional tolerances, form tolerances, straightness, twist, circularity, corner radii.