A. 10 mm
B. 5 mm
C. 1 mm
D. 12 mm
The question was asked in an interview for job.
This intriguing question comes from Construction of Screw Threads topic in division Curves used in Engineering Practice of Engineering Drawing
Explanation: In a double –threaded screw, the lead = the pitch of helix = 2 times of pitch of the screw. The pitch of screw = 10mm / 2 =5 mm. Even if the single- threaded screw is changed to double threaded screw the cross-section of thread and pitch of screw won’t change.