Dies are used for external threading. Manual threading is the most usual method although machine threading is sometimes used for simple tasks.

A solid die usually cuts more accurately than a split die. However, dies which are supplied solid may be split

Chromium Steel Tools
Thread cutting tools made from chromium steel are especially suited for manual threading. Chromium steels have a lower red hardness than high speed steels. This means that under comparable machining conditions, they will have less wear resistance than high speed steels.