Page 29 - CITS - Fitter Trade Practical - Volume -2

FITTER - CITS

Skill Sequence

Checking a tapered bore using a taper limit plug gauges
Objectives: At the end of this exercise you shall be able to
• check the internal taper with taper plug gauge.

A taper limit plug gauge ensures the accuracy of the angle and the linear dimensions of the taper bore. (Fig 1)

Fig 1

Clean the tapered bore.
Apply a thin layer of prussion blue on the traper limit plug gauge along its length (Fig 2)

Fig 2

Assemble the taper plug gauge inside the tapered bore carefully with sufficient force to ensure positive contact
between the gauge and the bore, and give on quarter twist to the plug gauge.
Carefully remove the taper limit plug gauge and check if the prussion blue is rubbed off uniformly, atleast to about
75% of its are. This ensures the accuracy of the angle required.

Then once again insert the taper plug gauge inside the taper bore and check, if the bid dia, end of the bore falls
within the ‘Go’ and ‘No-Go’ limits marked on the gauge, this ensures the dimensional accuracy of this tapered
bore. (Fig 3)

Fig 3

14

CITS : C G & M - Fitter - Exercise 59