Page 40 - CITS - Fitter Trade Practical - Volume -2
P. 40

FITTER - CITS

                                                                                          MODULE 7



           EXERCISE 62 : Mark off and drill through holes

            Objectives

           At the end of this exercise you shall be able to
           •   mark drill holes as per drawing
           •   drill through holes using pedestal drilling machine.








































            Job sequence

           •  Check the raw material for its size.
           •   File and finish to size 85 x 72 x 9 mm maintaining parallelism and perpendicularity.

           •   Mark drill holes as per drawing.
           •   Punch on drill hole centres using centre punch 90°
           •   Make centre drill in all drill hole centres.
           •   Fix 6 mm drill and drill pilot holes in all centre drilled holes.

           •   Similarly fix 8 mm, 10 mm, 12 mm and 16 mm drill in drilling machine and drill holes as per drawing.
           •   Finish file and de-burr in all the surfaces of the job.
           •   Check the size with vernier caliper.
           •   Apply a thin coat of oil and preserve it for evaluation.









                                                           25
   35   36   37   38   39   40   41   42   43   44   45