Temper is the hardness or strength of materials. Temper ranges from dead soft to full hard and any increment within those ends. With typical copper alloys the degree of softness is obtained from anneal temperature and time at temperature. Hardness is developed from the cold reduction of the soft tube by control of the amount of cold work reduction. Continued reductions without further annealing results in tempers ranging from the fractional hards to full hard condition. It is noteworthy that annealing can not produce a partial hardness, it can only produce soft tube. Rod, bar, and strip all react the same as tube.

Temper available from STP (ranked from softest to hardest)

1. Soft Anneal (O60)
2. Medium Anneal
3. Light Anneal (O50)
4. Annealed and Rotary Straightened
5. ¼ Hard
6. ½ Hard or Light Drawn (H55)
7. ¾ Hard
8. As Drawn / Drawn (H58)
9. Hard (H80)