Home › Steel › Tempering Tools

Tempering Tools

The steel is generally first hardened by heating it to a cherry red, and then plunging it into cold water. Afterward the temper is drawn by moderately heating the steel again. Different degrees of hardness are required for different purposes.

For very pale straw color, 430°, for lancets.

A shade of darker yellow, 450°, for razors and surgical instruments.

Darker straw yellow, 470°, for pen-knives.

Still darker yellow, 490°, chisel for cutting iron.

Brown yellow, 500°, axes and plane-irons.

Yellow, slightly tinged with purple, 5200, table-knives and watch-springs.