Page 73 - CITS - Fitter Trade Pactical - Volume - 2

FITTER - CITS

EXERCISE 20: Exercise on scraping practice on cast iron

surface plate

Objectives

At the end of this exercise, you will be able to
• file surfaces flat and square to the accuracy of ± 0.04 mm
• find high spot on flat surfaces using prussion blue
• scrap on the flat surfaces and test.

Job Sequence
Job Sequence
Scraping on Flat Surface
• Check the raw material for its size.
• File metal to size 72x72x10 mm maintaining flatness and squareness..

• Check the size with vernier caliper.
• Clean the surface plate with soft cloth.
• Apply prussion blue evenly on the surface plate.
• Place the job on surface plate and move slightly forward and backward.

• Take the job from surface plate and notice the blue spotted marks on the flat surface.
• Hold the job in bench vice.
• Scrap and remove the high spots on the flat surface of the job using flat scraper Fig 1.

Fig 1

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