Piece of red hot glowing metal in forge Piece of red hot glowing metal in forge

Tempers Guide

What is Metal Tempering?

Tempering metal is a heat treatment process of heating metals to their lower critical temperature. This process hardens the metal and produces enhanced properties. These properties can include increased hardness and impact-resistant material, better corrosion resistance, and increased flexibility. Some tempered metals are a better fit for specific applications because of their physical properties, such as marine, structural, or niche machining practices.

Temper Chart

A letter and number identify the tempered metal. These designations show the response of the material to the heat treatment, allowing the user to select the correct alloy for their project letter and number after the alloy number. For example, Aluminum 6063-T52, where T52 is the aluminum temper. Copper temper, brass temper, and bronze temper are also indicated by a letter and number. To decide which metal temper is right for your application, refer to the chart below which lists copper temper, brass temper, and aluminum temper.

Copper, Brass, and Bronze

Copper, Brass, and Bronze



When is it used?

Temper: O60

Description: Annealed

When it's used: Applications that require ease of forming and bending.

Temper: H00

Description: 1/8 Hard

When it's used:Forming applications where more resistance to the stresses of expansion and contraction are required.

Temper: H01

Description: ¼ Hard

When it's used:Applications where strength and malleability are both important.

Temper: H02

Description: ½ Hard

When it's used: Most construction applications where strength is most important.

Temper: H04

Description: Full Hard

When it's used: Round bar stock where high strength is required.

Temper: H58

Description: Drawn General Purpose

When it's used:General purpose tube where strength and hardness are not required.

Temper: H80

Description: Hard Drawn

When it's used: High pressure tube applications and where strength is required.

Temper: M07

Description: As-continuous cast

When it's used:A better quality more cost effective cast bar product that requires machining to finished dimensions.

Temper: M20

Description: As-hot rolled

When it's used:Manufactured temper for hot worked bar and plate.

Temper: M30

Description: As-hot extruded

When it's used: Manufactured temper for hot extruded shapes.