Lexicon DIY-Knowledge



Machos de roscar


Taps are application tools used to cut threads in metal and plastic. Standard manual tap drills are unsuitable for this purpose and instead spiral-fluted machine taps have to be used.

The required core hole diameter for hand-cut threads with a three-piece tap set is calculated with the following rule of thumb:

core hole = thread diameter x 0.8

For threads cut with machine taps (so-called bottoming taps) you can use the formula:

core hole = nominal thread diameter
core hole = minus thread pitch