Question

Which of the following screw thread is adaptable to split type nut?

(a) square thread

(b) trapezoidal threads

(c) buttress threads

(d) v threads

This question was addressed to me in a job interview.

This key question is from Friction of a V-thread in division Friction of Machine Kinematics

Answer 1

Correct choice is (b) trapezoidal threads

For explanation: An acme or trapezoidal thread, is a modification of square thread. The slight slope given to its sides lowers the efficiency slightly than square thread and it also introduce some bursting pressure on the nut, but increases its area in shear. It is used where a split nut is required and where provision is made to take up wear as in the lead screw of a lathe.