Threading Tools

Threading tools

This category covers everything you need to cut and repair threads. Use a tap for internal threads. Use a die for external threads. The tools are divided into seven groups: taps, dies, holders, repair kits, files, sets and accessories.

Taps and dies

Taps come in sets of three: taper, plug and bottoming. This lets you cut an internal thread in one pass. Choose the tap based on the bore and the pitch. The same applies to threading dies. These cut external threads on a bolt or shaft. Always check the diameter and pitch. A wrong choice gives a poor fit.

Holders and repair

A tool holder clamps the tap or die securely. A tap wrench grips the tap, a die stock holds the die. This keeps the tool square to the workpiece. If the thread is damaged, use thread repair tools. These restore the original size. First measure the pitch and diameter of the existing thread.

Files, sets and accessories

A thread file repairs minor damage to internal and external threads. Choose the pitch for metric, SAE or Whitworth. For the workshop, assortments are practical. They contain multiple tap and die sizes in one case. With accessories such as thread pitch gauges you check the pitch of an existing thread. This ensures you always pick the right size.

How to choose

For a new internal thread, choose a tap set. For a new external thread, choose a die. If the thread is damaged, use a repair kit or thread file. Make sure you have the right holder. With the wrong tool you will break the tap or get a rough thread.