Tantung How To Grind

Tantung tools are not hard to grind but they can be cracked and checked by overlooking a few simple precautions.

The usual elements of good grinding practice should be observed as follows:

DO

Select proper grinding wheel. It is desirable to use slightly softer grades than would be used for high speed steel. Operate wheel in proper speed range. Refer to suggestions in table below. Use liberal supply of coolant or none at all. Cut-off wheels should be run dry. Traverse the work continually with respect to the wheel in order to avoid local overheating. Dress the wheel as often as necessary to keep it free cutting.

DON'T

Don't quench a tool after grinding. Don't use excessively hard or glazed wheels. Don't use to heavy pressure. Don't use dribbling coolant.

Simple tools can be ground offhand. Machine grinding is preferable, especially for form tools and when accuracy is required. The machine should be provided with tool rests graduated for correct angle measurement.

The cast-cutting alloys are heat sensitive. They can be damaged or ruined by poor grinding practice which causes checking of the surface.

SUGGESTIONS FOR GRINDING WHEEL SELECTION

GRINDING OPERATION	WHEEL ELEMENTS					WHEEL SPEED IN SURFACE FEET PER MINUTE
	ABRASIVE	GRAIN SIZE	GRADE	STRUCTURE	BOND
Offhand: Roughing	Aluminum Oxide	60	K	6	Vitrified	3800-4200
Finishing	Aluminum Oxide	60	I	6	Vitrified	3800-4200
Machine: Roughing	Aluminum Oxide	60	I	8	Vitrified	3800-4200
Finishing	Aluminum Oxide	60	I	6	Vitrified	3800-4200
Forming	Aluminum Oxide	100	I	6	Vitrified	3800-4200
Crush Forming	Aluminum Oxide	220	J	13	Vitrified	3800-4200 Use liberal flow of No. 6 oil
Cutting Off	Aluminum Oxide	30	A	5	Vitrified	11,000(Grind Dry)