NO Go passing Problem - Tap Cutting in Reverse Direction
Problem: NO GO Passing
Tapping Size: M8 (SPPT) 18 mm
Spindle RPM: 200 rpm.
Description: The trial of tapping attachment was carried out on a cylindrical head (Material Cast iron) with M8 Spiral point (SPPT) tap for through tapping(Length=18mm). Trial was carried out at 200rpm.
On Testing it was found that No GO Gauge was passing. Different speeds were tried but the problem was persistent. We also tried changing the torque setting but no change was observed.
One more trial was taken. This time we did the tapping in the forward direction & then manually removed the tap from the bottom of of the tapped hole.
We found that NO GO wasn't passing. This meant that the tap was cutting in the reverse direction.
Solution: Thus problem was basically in the tap & after replacing the tap with proper geometry solved the problem.