Hand drilling and tapping

[sdelivery]

I have several of these with different size holes.
I use them to assist in straight holes and straight taped holes.
This one in the pictures is for taps.
There is roughly. 001 to .002 clearance for the tap.
Same when I do the drill blocks. I ream them before heat treatment.

 

[markba633csi]

Those are great- I used to know the name for them- tap buttons?
I usually make dedicated ones for the job at hand being a basically lazy, addled person. I should make a multi-size one like yours
-Mark