Heat Treatment

The finished workpiece must generally be hardened for various reasons:

• Reducing mechanical wear (increasing service life);
• Ease of assembly;
• Ensuring proper function (such as for test plungers)

Structural hardening takes place on heating the pieces between 800 and 1000 degrees Celsius and subsequent rapid cooling. Although this treatment makes the steel harder, it also becomes more brittle and thus more fragile.

To regain the necessary elasticity, the pieces are heated again (the temperature depends on the desired hardness) and then slowly cooled. This operation is called «tempering».