The American Society for Testing and Materials (ASTM) has established a unified system for expressing temper designations for copper, aluminum, magnesium, and their products.

Basic Temper Designations

• O — Annealed: Material in the annealed condition to meet mechanical property requirements.

• OS — Annealed for Grain Size: Material in the annealed condition to meet special grain size requirements specified by standards.

• M — As-Fabricated: Cast or hot-formed condition; various control measures are applied during production.

• H — Cold-Worked: Material in the cold-worked condition obtained by controlling the amount of cold work.

• HR — Cold-Worked and Stress-Relieved: Material cold-worked to a specified degree and then stress-relieved.

• HT — Strain-Hardened and Thermally Treated: Material cold-worked and subsequently thermally treated to achieve strain-hardening.

• T — Heat-Treated: Material rapidly cooled after heat treatment.

• W — Welded Tube: Made by welding strips or sheets of various tempers; apart from heat-affected zones, the welded tube retains the same temper as the original material.

Subdivisions of O Tempers

• O10 — Cast and Annealed (Homogenized)

• O11 — Cast and Precipitation Heat-Treated

• O20 — Hot Forged and Annealed

• O25 — Hot Rolled and Annealed

• O30 — Hot Extruded and Annealed

• O31 — Extruded and Precipitation Heat-Treated

• O40 — Hot Pierced and Annealed

• O51 — Lightly Annealed

• O60 — Soft Annealed

• O61 — Annealed

• O65 — Drawn and Annealed

• O68 — Deep Drawn and Annealed

• O70 — Fully Soft Annealed

• O80 — Annealed to 1/8 Hard

• O81 — Annealed to 1/4 Hard

• O82 — Annealed to 1/2 Hard

Subdivisions of OS Tempers (Annealed for Grain Size)

• OS005 — Annealed, average grain size 0.005 mm

• OS010 — Annealed, average grain size 0.010 mm

• OS015 — Annealed, average grain size 0.015 mm

• OS025 — Annealed, average grain size 0.025 mm

• OS035 — Annealed, average grain size 0.035 mm

• OS050 — Annealed, average grain size 0.050 mm

• OS060 — Annealed, average grain size 0.060 mm

• OS070 — Annealed, average grain size 0.070 mm

• OS100 — Annealed, average grain size 0.100 mm

• OS120 — Annealed, average grain size 0.120 mm

• OS150 — Annealed, average grain size 0.150 mm

• OS200 — Annealed, average grain size 0.200 mm

Subdivisions of M Tempers (As-Fabricated)

• M01 — Sand Casting

• M02 — Centrifugal Casting

• M03 — Plaster Mold Casting

• M04 — Die Casting

• M05 — Metal Mold Casting

• M06 — Investment Casting

• M07 — Continuous Casting

• M10 — Hot Forged — Air Cooled

• M11 — Forged — Quenched

• M20 — Hot Rolled

• M30 — Hot Extruded

• M40 — Hot Pierced

• M45 — Hot Pierced and Re-Rolled

Subdivisions of H Tempers (Cold-Worked)

• H00 — 1/8 Hard

• H01 — 1/4 Hard

• H02 — 1/2 Hard

• H03 — 3/4 Hard

• H04 — Hard

• H06 — Extra Hard

• H08 — Elastic

• H10 — High Elastic

• H12 — Special Elastic

• H13 — Ultra-High Elastic

• H14 — Maximum Elastic

Additional H variants correspond to specific operations:

• H50 — Extruded and Drawn

• H52 — Pierced and Drawn

• H55 — Lightly Drawn / Lightly Cold-Rolled

• H58 — General Drawing

• H60 — Cold Heading / Forming

• H63 — Riveting

• H64 — Screw

• H66 — Bolt

• H70 — Bending

• H80 — Drawn Hard

• H85 — Drawn Half-Hard Wire

• H86 — Drawn Hard Wire

Subdivisions of HR Tempers (Cold-Worked and Stress-Relieved)

• HR01 — 1/4 Hard, Stress-Relieved

• HR04 — Hard, Stress-Relieved

• HR02 — 1/2 Hard, Stress-Relieved

• HR08 — Elastic, Stress-Relieved

• HR10 — High Elastic, Stress-Relieved

• HR50 — Drawn and Stress-Relieved

Subdivisions of HT Tempers (Strain-Hardened and Thermally Treated)

• HT04 — Hard, Heat-Treated

• HT08 — Elastic, Heat-Treated

Subdivisions of T Tempers (Heat-Treated)

TQ (Quench-Hardened Condition):

TQ00 — Quench-Hardened

TQ50 — Quench-Hardened and Tempered

TQ55 — Quench-Hardened, Tempered, Cold-Drawn and Stress-Relieved

TQ75 — Step Quench

TB (Solution Heat-Treated Condition):

TB00 — Solution Heat-Treated

TD (Solution Heat-Treated and Cold-Worked):

TD00 — Solution Heat-Treated, Cold-Worked to 1/8 Hard

TD01 — …to 1/4 Hard

TD02 — …to 1/2 Hard

TD04 — …to Hard

TF (Solution Heat-Treated and Precipitation Hardened):

TF00 — Precipitation-Hardened (AT)

TX (Solution Heat-Treated and Spinodal Hardened):

TX00 — Spinodal-Hardened (AT)

TH (Solution Heat-Treated, Cold-Worked, and Precipitation-Hardened):

TH01 — 1/4 Hard, Precipitation-Hardened

TH02 — 1/2 Hard, Precipitation-Hardened

TH03 — 3/4 Hard, Precipitation-Hardened

TH04 — Hard, Precipitation-Hardened

TS (Cold-Worked and Spinodal-Hardened to Meet Standard Requirements):

TS00 — 1/8 Hard, Spinodal-Hardened

TS01 — 1/4 Hard, Spinodal-Hardened

…

TS14 — Maximum Elastic, Spinodal-Hardened

TM (Cold-Worked and Precipitation/Spinodal Heat-Treated, Rolled for Delivery):

TM00 — Rolled to 1/8 Hard after Heat Treatment

TM01 — …to 1/4 Hard

…

TM08 — Rolled to Elastic after Heat Treatment

TL (Precipitation/Spinodal Heat-Treated and Cold-Worked):

TL00 — Cold-Worked to 1/8 Hard after Precipitation/Spinodal Heat Treatment

…

TL10 — Cold-Worked to High Elastic

TR (Precipitation/Spinodal Heat-Treated, Cold-Worked, and Stress-Relieved):

TR01 — Cold-Worked to 1/4 Hard and Stress-Relieved

TR02 — Cold-Worked to 1/2 Hard and Stress-Relieved

TR04 — Cold-Worked to Hard and Stress-Relieved

Subdivisions of W Tempers (Welded Tubes)

WM (Welded Condition):

WM50 — Welded from Annealed Strip

WM00 — Welded from 1/8 Hard Strip

WM01 — Welded from 1/4 Hard Strip

…

WM22 — Welded from 1/2 Hard Strip Stress-Relieved

WO (Post-Weld Annealed):

WO50 — Welded and Bright Annealed

WH (Post-Weld Cold-Drawn):

WH00 — Cold-Drawn 1/8 Hard

WH01 — Cold-Drawn 1/4 Hard

WR (Post-Weld Cold-Drawn and Stress-Relieved):

WR00 — Cold-Drawn and Stress-Relieved 1/8 Hard

WR01 — Cold-Drawn and Stress-Relieved 1/4 Hard