Question

For acme thread, the angle between the two flanks is ____

(a) 55 degrees

(b) 47.5 degrees

(c) 29 degrees

(d) 45 degrees

The question was posed to me during an interview.

This key question is from Screw Threads in section Screw Threads & Screwed Fastening of Engineering Drawing

Answer 1

Right answer is (c) 29 degrees

To explain I would say: For Whitworth thread the angle between the two flanks is 55 degrees, for British association thread the angle between the two flanks is 47.5 degrees, for acme thread the angle between the two flanks is 29 degrees.