Page 76 - CITS - Fitter Trade Pactical - Volume - 2

FITTER - CITS

Use a master bar to check the correctness of the surface being scraped. (Fig 5)

Note: Apply a thin coating of Prussion blue on the master bar to locate the high spots.

Fig 5

Sharpening a flat scraper
Objectives: At the end of this exercise you shall be able to
• sharpen a flat scraper by grinding and honing.

Flat scrapers are sharpened by grinding the cutting edge and honing both faces.
To avoid overheating while grinding, use wet wheel grinding or ensure that there is a cooling arrangement for the
pedestal/bench grinder.
Select a grinding wheel with fine grain. (Fig 1)

Fig 1

Soft grade aluminium oxide grinding wheel with large diameter gives best results
Note: Check for gap between the work-rest and the grinding wheel, and adjust, if neessary.

For grinding the cutting edges, hold the scraper horizontal and flat on the tool rest. (Fig 2)
Fig 2

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CITS : CG & M - Fitter - Exercise 21