Taper, Plug and Bottoming -- What is the big freakin’ difference?

Taper, Plug and Bottoming -- What is the big freakin’ difference?

Taper, Plug and Bottoming --  What is the big freakin’ difference?

The most common hand taps are called taper, plug, and bottoming.

All three look very similar with the only difference being the bevel angle at the tip (the amount of threading on the tip).



Taper, Plug and Bottoming Compartive View

Taper, Plug and Bottoming are identical except for the bevel angle at the tip. The bevel serves two purposes: it guides the tap into the hole and it ramp cuts the undeveloped first threads.

Taper taps have the longest bevel angle.
Plug taps are the most common and have 3 to 5 undeveloped threads on the bevel.
Bottoming taps have only 1 to 1 1/2 undeveloped threads at the tip and should be used only when full amount of threads cannot be achieved by the other two taps.
The number of flutes and the geometry of the cutting edge will depend on the material tapped.