AndyStobbs
Member
- Messages
- 2,475
- Location
- North West England
While waiting in my local fastener shop earlier this week, I was reading a table giving drill sizes for tapping metric threads. It stated all the usual stuff about subtracting pitch from major diameter to give drill size. But went on to say that this method will cut 82% of the thread form. This was unknown to me, and got me wondering if machine taps cut a full 100%?