Aluminum Alloy Temper Explained Guide for Industrial Buyers

Aluminum Alloy Temper Explained: O, H, T5, T6 and Other Common Conditions

Aluminum alloy grade alone does not define material performance. The temper is also important.

For example, 6061-O and 6061-T6 have the same base alloy designation. Their strength and forming behavior are very different. The same applies to 5052-O and 5052-H32.

Industrial buyers should therefore specify both the alloy and temper when requesting aluminum sheet, plate, coil, bar or profile.

What Does Aluminum Temper Mean?

An aluminum temper identifies the condition produced by thermal treatment, strain hardening or a combination of processing steps.

The temper designation follows the alloy number. Examples include:
*5052-H32

*5083-H116

*6061-T6

*6063-T5

*7075-T6

Temper designation systems are standardized for wrought aluminum products. ISO 2107 establishes temper designations for wrought aluminum and aluminum alloys. EN 515 serves a similar role in European specifications.

Main Aluminum Temper Designations

Temper	General Meaning	Typical Buyer Focus
F	As fabricated	Properties depend on the manufacturing process
O	Annealed	High formability and lower strength
H	Strain hardened	Common for non-heat-treatable alloys
W	Solution heat-treated unstable condition	Usually an intermediate condition
T	Thermally treated to produce stable tempers other than F, O or H	Common for heat-treatable alloys such as 6061 and 7075

Understanding H Tempers

H tempers are commonly used with non-heat-treatable aluminum alloys. Examples include many 3xxx and 5xxx series products.

The numbers following H provide more information about the processing condition.

Example	General Description	Typical Use
H12 / H14	Strain-hardened conditions with different strength levels	General sheet and fabrication
H22 / H24	Strain hardened and partially annealed	Formed sheet and coil products
H32 / H34	Strain hardened and stabilized	Common in 5xxx series sheet and plate

Example: 5052-H32 is widely used where good corrosion resistance and practical forming performance are required.

T5 vs T6 Aluminum Temper

T5 and T6 are common tempers for heat-treatable aluminum alloys. They should not be treated as the same condition.

Temper	Processing Route	Common Application
T5	Cooled from an elevated-temperature shaping process and artificially aged	Common in extruded profiles such as 6063-T5
T6	Solution heat-treated and artificially aged	Structural, machined and higher-strength applications

6061-T6 is often chosen for structural and machined parts. 6063-T5 is common for architectural extrusions.

The final choice should follow the drawing and required mechanical properties.

Common Alloy and Temper Combinations

Alloy & Temper	Main Characteristic	Typical Application
3003-H14	Good formability and moderate strength	General sheet fabrication
5052-H32	Good corrosion resistance and forming performance	Marine and industrial sheet components
5083-H116	Used for specified marine applications	Shipbuilding and marine structures
6061-T6	Good strength and machinability	Structural and machined components
6063-T5	Good extrusion and surface quality	Architectural profiles
7075-T6	High strength	High-load and aerospace-related components where specified

Standards Buyers Should Know

Standard	Purpose
ISO 2107	Temper designations for wrought aluminum and aluminum alloys
EN 515	European temper designation system for wrought aluminum products
ASTM B209/B209M	Aluminum and aluminum-alloy sheet and plate in specified alloys and tempers

ASTM B209 does not define every aluminum product form. Extruded, drawn and other products can require different specifications.

How to Choose the Right Aluminum Temper

Requirement	Temper Direction
Maximum forming ability	Consider softer conditions such as O where available
Higher strength in non-heat-treatable alloy	Consider suitable H temper
Structural strength	T6 may be suitable for certain heat-treatable alloys
Architectural extrusion	T5 or T6 depending on profile and property requirements
Marine plate	Use the alloy and temper required by the applicable marine specification

Buyer tip: never change the temper simply because the base alloy is the same. Mechanical properties and fabrication behavior may change significantly.

What to Include in an Aluminum RFQ

• Alloy grade
• Temper
• Product form
• Thickness or diameter
• Width and length
• Quantity
• Applicable standard
• Dimensional tolerance
• Surface condition or coating
• Inspection and certificate requirements

FAQ

What does T6 mean in aluminum?

T6 identifies a solution heat-treated and artificially aged temper. It is commonly used for heat-treatable alloys such as 6061.

What does H32 mean in aluminum?

H32 is a strain-hardened and stabilized temper. It is commonly seen in 5xxx series aluminum products such as 5052-H32.

Is T6 stronger than O temper?

For a heat-treatable alloy that can be supplied in both conditions, T6 generally provides much higher strength than O. O temper usually provides better formability.

What is the difference between T5 and T6?

T5 is artificially aged after cooling from an elevated-temperature shaping process. T6 involves solution heat treatment followed by artificial aging.

Can I change from H32 to H34 without affecting the part?

Do not assume so. Different H tempers can have different strength and formability. Any change should be checked against the drawing and required mechanical properties.