Question

Which of the following is incorrect for the minor diameter tolerance of effective diameter for internal threads?

(a) For 26 tpi : Tolerance = 0.2p+0.004”

(b) For 26 tpi : Tolerance = 0.2p+0.005”

(c) For 22 tpi : Tolerance = 0.2p+0.005”

(d) For 26 tpi : Tolerance = 0.2p+0.007”

This question was posed to me in quiz.

My query is from Tolerance for Screw Thread Gauges and Screw Threads in division Metrology of Screw Thread, Gauges for ISO Metric Screw Threads of Engineering Metrology

Answer 1

Right option is (b) For 26 tpi : Tolerance = 0.2p+0.005”

Explanation: For minor diameter tolerance of internal threads, tolerance for 26 tpi and finer is equal to 0.2p + 0.004”, tolerance for 24 tpi and 22 tpi is equal to 0.2p+0.004”, tolerance for 20 tpi and coarser is equal to 0.2p+0.004”.