Page 92 - CITS - Fitter Trade Pactical - Volume - 2

FITTER - CITS

EXERCISE 28: Practice on drilling through and blind
holes on ferrous & non-ferrous metals to a

positional accuracy of ±0.10mm

Objectives

At the end of this exercise you shall be able to
• mark drill hole centres using vernier height gauge
• set the correct spindle speed in drilling machine
• drill through hole as per drawing
• set the depth bar to drill blind hole
• drill blind hole to the required depth size.
• drill on ferrous and non- ferrous metal.

Job Sequence

• Check the raw material size.

• File and finish the metal to size 60 x 60 x 19 mm maintaining parallelism and perpendicularity.
• Check the flatness and squareness with try square and size with vernier caliper.
• Apply marking media and mark drill holes centres using vernier height gauge as per drawing.
• Punch on drill holes centres using centre punch 90°
• Hold the job in drilling machine table.

• Make centre drill in drill holes centres.

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CITS : CG & M - Fitter - Exercise 27