Question

A double –threaded screw has a pitch of screw 2 mm. How much the screw advances if it is made 3 revolutions?

(a) 5

(b) 6

(c) 12

(d) 10

This question was addressed to me by my school teacher while I was bunking the class.

The above asked question is from Construction of Screw Threads topic in section Curves used in Engineering Practice of Engineering Drawing

Answer 1

Right choice is (c) 12

To elaborate: It is given the screw is double- threaded screw which advances to a distance of 2 times the pitch of screw for one complete turn also given pitch of 2 mm. so for one turn the screw advances to 2 x 2mm = 4 mm. The screw is made to turn 3 revolutions so the screw advances to 3 x 4 mm =12 mm.