Machining Tip #1 - Threading
MACHINING TIP / Threading
When forming a thread, the tapping hole size depends on the work-piece material being drilled, the cutting conditions selected and the equipment used.
If material is pushed up at the thread entry by the tap and/or the life of the tap is too short, select a slightly larger drill diameter. If the profile of the thread formed is insufficient, then select a slightly smaller drill diameter.