Question

What is the permissible error in working accuracy of cylindrical turning when a job is held between centers when a practical test is performed?

(a) 0.02mm/100 mm

(b) 0.01mm/100mm

(c) 0.02mm/300 mm

(d) 0.01mm/300 mm

The question was asked in an interview for job.

I would like to ask this question from Alignment Tests on Lathe topic in division Machine Tool Metrology of Engineering Metrology

Answer 1

Correct option is (c) 0.02mm/300 mm

To elaborate: Working accuracy of machine facing is a permissible error of 0.02 mm over the diameter of test work piece, which is taken as 300 mm for swing over bed of upto 500 mm, and 400 mm for swing over 500 mm. Hence the permissible error is 0.02 mm/300 mm.