Taps are an important part of the machinist's tool kit.
Taps are case-hardened steel tools that are usually used to cut threads in nuts and metal surfaces. Taps are most often used to "chase," or refresh, these threads rather than cut new ones. Sometimes, however, taps are used to cut an unthreaded, but nevertheless precise, shape in raw metal. When taps become dull they lose their precision and produce threads that are too large or too small. The duller a tap becomes, the more likely it is to break.
Instructions
1. Look at the cutting end of the tap. The four grooves at the end of the tap are called chamfers. These grooves are shaped like a cloverleaf. The four small blades are called flutes. The sharp point in the middle of the end of the tap is called the point.
2. Insert the tap to be sharpened vertically in a vise fitted with aluminum jaw inserts. Inspect the tap. As you view the tap from above, only the left side of the four chamfers in a tap designed to cut right-handed threads need to be sharpened.
3. Remove any burrs from the point using light strokes of a die grinder fitted with a round grinder stone.
4. Recondition taps by lightly grinding the chamfers' cutting edges, under the flute, with a die grinder and a round grinder stone.
