Aluminum Temper Designations for Product Procurement

Overview

An aluminum temper designation records the processing condition applied after alloy production. F, O, H, W and T families distinguish fabrication, annealing, strain hardening, solution heat treatment and thermally treated conditions, but exact properties remain product- and thickness-dependent.

Designation and acceptance

ANSI H35.1/H35.1M defines alloy and temper designation systems for aluminum. The temper follows the alloy number and can include digits describing operation sequences or degrees of strain hardening. A temper is meaningful only with the exact alloy, wrought or cast product form, governing specification and dimensional range.

Members and selection

Comparison framework

Performance

• Strength and elongation depend jointly on alloy, temper, product form and section size.
• Toughness, corrosion and stress-corrosion behavior can change between tempers of the same alloy.
• Electrical and thermal response may be affected by cold work and precipitation treatment.

Orderable product scope

• Rolled sheet, plate and foil require exact alloy-temper, gauge range, finish and flat-product specification.
• Extrusions and drawn products require alloy-temper plus profile, wall thickness and product tolerances.
• Forgings and castings require process-specific condition, heat treatment and mechanical-test locations.

Processing

• Assess whether forming, brazing, welding, painting bake or service temperature will modify the ordered temper.
• Control natural- and artificial-aging time where an unstable or age-sensitive condition is involved.
• Keep full temper suffixes on drawings, purchase orders, labels and certificates to prevent condition substitution.

Applications

• Choosing formable annealed sheet versus strain-hardened sheet for fabricated enclosures.
• Specifying heat-treated plate or extrusion for structural components with defined properties.
• Comparing supplier offers that use the same alloy but different tempers or product standards.

Selection

• Select alloy for environment and manufacturing route, then choose temper for forming and final property needs.
• Check the product specification and thickness-dependent property table for the full alloy-temper combination.
• Review downstream thermal and mechanical processing before fixing acceptance properties.

Procurement

• State the complete alloy and temper designation together.
• State the product form, governing specification, dimensions and tolerance class.
• Define required mechanical properties, surface condition and downstream processing assumptions.
• Specify testing, certificate, marking, lot traceability, packaging and substitution approval.

Sources and review

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