Question

What are the values of constants for whit worth threads?

(a) a=0.003 b=0.005, c=0.002

(b) a=0.002, b=0.003, c=0.005

(c) a=0.004, b=0.005, c=0.006

(d) a=0.001, b=0.002, c=0.003

This question was addressed to me in exam.

This question is from Tolerance for Screw Thread Gauges and Screw Threads in section Metrology of Screw Thread, Gauges for ISO Metric Screw Threads of Engineering Metrology

Answer 1

Right choice is (b) a=0.002, b=0.003, c=0.005

The best I can explain: The value of these constants according to British Standard Specifications for Whitworth threads for medium fit are a=0.002, b=0.003, c=0.005 i.e. the equation of tolerance on effective diameter is 0.002∛D  +0.003√L  +0.005√