Page 159 - CITS - Fitter Trade Pactical - Volume - 2

FITTER - CITS

EXERCISE 44: Exercise on advanced practice on making

filing etc

Objectives

At the end of this exercise you shall be able to
• make right angle surface
• make accurate surface
• make close dimension with accuracy 0.02mm.

Procedure

1 Check the raw material for its size with a steel rule 300mm.
2 Hold the workpiece in a 125mm jaw bench vice on its ends.
3 Ensure the work is held horizontally.
4 File the top surface with a flat bastard file 250mm.
5 Check flatness with a try-square.
6 File to medium finish using a flat second cut file 250mm.
7 Hold the workpiece to file the longer side.
8 File and check flatness and squareness with previously finished surfaces using a try-square 150mm.
9 File the adjacent shorter side flat and square to both the finished surface.
10 Remove burrs and mark sizes as per job drawing, using a steel rule, try-square and scriber.
11 File the other two sides flat and square, maintaining the dimensions.
12 File the other flat surface parallel and check the thickness using an Vernier caliper.
13 Remove burrs, using a flat second cut file.
Safety Precautions
1 Read the drawing thoroughly.
2 Don’t use file without handle.
3 Remove the sharp edge / burrs of the job using second cut files.
4 Don’t use the oil / grease on the file or job surface.
5 Handle carefully precision measuring instruments.
6 Don’t mix precision measuring instruments with cutting tools.
7 Use filing speed as per material of the job.
8 Select correct pitch of the blade as per raw material in hacksawing.
9 check squareness carefully
10 Take high spot using Prussian blue on surface plate.

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