Question

What is the tolerance of parallelism of straight lines?

(a) 0.015 on 300 mm

(b) 0.15 on 300 mm

(c) 0.015 on 600 mm

(d) 0.15 on 600 mm

I got this question at a job interview.

This interesting question is from Parallelism, Equidistance and Coincidence in chapter Straightness, Flatness, Squareness, Parallelism, Circularity and Rotation of Engineering Metrology

Answer 1

Correct answer is (a) 0.015 on 300 mm

Explanation: Permissible deviations or tolerance of parallelism of two plane surfaces or straight lines is 0.015 mm on 300 mm.  Free end of the spindle relative to the table surface is in upward direction only.