Question

A three-start external square thread of 12 mm pitch and outside diameter of 65 mm is to be cut on a centre lathe which has a 7 mm pitch lead screw. Depth of thread to give 0.14 clearance is _______ mm.

• A. 6.14

Answer 1

The correct option is A 6.14
$\text{Depth of thread to give clearance of}0.14\text{mm}=6+0.14=6.14\text{mm}$
$\text{Depth of square thread}=\frac{\text{pitch}}{2}=\frac{12}{2}=6\text{mm}$