Question

How correctness of taper can be checked?

(a) Draw a single line of Persian blue along the length

(b) Draw two lines of Persian blue at any distance along the diameter

(c) Draw three lines of Persian blue at equidistant along the length

(d) No need of Persian blue, it can be checked simply by seeing the rotation of spindle

I have been asked this question during an interview for a job.

The above asked question is from Gauges for Tapers topic in portion Limits, Fits and Gauges of Engineering Metrology

Answer 1

Correct choice is (c) Draw three lines of Persian blue at equidistant along the length

Best explanation: 3 lines are drawn with Persian blue along the length on the plug gauge or spindle to test the taper. It is fitted in the gauge and rotated once or twice. If these marks of Persian blue are not rubbed evenly then the taper is not correct.