Page 107 - CITS - Fitter Trade Pactical - Volume - 2

FITTER - CITS

EXERCISE 31: Demonstration and exercise on counter

bore, counter sink, spot facing reaming
holes - three pieces fitting with dowel pins

Objectives

At the end of this exercise you shall be able to
• mark the lines as per job drawing
• drill, counter sink, counter bore and ream the holes as per drawing
• drill, spot face as per drawing .
• cut and remove excess metal in part 1, 2 and 3.
• file and finish to size and shape,
• make and fit using dowel pins as per drawing.

Job Sequence

• Check the raw material for its size.
• File and finish to over all size of part 1 and 2 to 80x50x9 mm, part 3 to the size of 40x30x9 mm maintaining
parallelism and perpendicularity.
• Mark the hole centres using centre punch and punching in part 1, 2 and 3 as per drawing..

• Mark the hole centres using centre drill .
• Fix the job in drilling machine table with suitable clamps.
• Fix centre drill in drilling machine spindle through drill chuck and drill centre drilling in all drill holes centres.
• Fix Ø 6 mm drill in drill chuck and drill through holes a sper drawing in all centre in drilled holes.

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