Page 220 - CITS - Fitter Trade Practical - Volume -2

FITTER - CITS

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

Fig 1 Fig 2

Move the scraper in an arc to provide a slightly concave surface on the cutting edge. (Fig 3)
If the scraper is carbide-tipped use silicon carbide or diamond wheels. (Fig 4)

Fig 3 Fig 4

The cutting edges sharpened by grinding should be honed. Honing removes grinding marks and provides keen
cutting edges.

Use a fine grade aluminium oxide oilstone for honing.
While honing use a lubricant.
Mix light mineral oil with kerosene for preparing the lubricant.
Hone the faces first with a movement as shown in Fig 5. Then hone the cutting end by placing the scraper in an
upright position on the oilstone with a rocking movement. (Figs 6 and 7)

Fig 5 Fig 6

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CITS : C G & M - Fitter - Exercise 91