Machining

Key factors for successful machining are proper machining speeds and coolant. Macor MGC can be machined with high-speed steel tools, but carbide tools are recommended for longer wear. Achieve the best results by using a water-soluble coolant especially formulated for cutting and grinding glass or ceramics.

No post firing is required after machining.

Sawing

Use a carbide grit blade at a band speed of 100fpm. (30.5m/min). An alternative is a silicon carbide or diamond cut-off wheel.

Turning

Cutting speed . . . . 30-50sfm (9-15m/min)

Feed rate . . . . . . . 002-.005ipr (0.005-0.013cm/rev)

Depth of cut . . . . . 150-.250in. (0.38-0.64cm)

Milling

Cutting speed . . . . . 20-35sfm (6.1-10.7m/min)

Chip load . . . . . . .   .002ipt (0.05mm per tooth)

Depth of cut . . . . . . 150-. 200in. (0.38-0.51cm)

Drilling

Allow at least 0.50in (0.13cm) of extra material on the backside for breakout. This excess can be moved after drilling.

Tapping

Make clearance holes one size larger than those recommended for metals. Chamfer both ends of the hole to reduce chipping. Run the tap in one direction only. Turning the tap back and forth can cause chipping. Continuously flush with water or coolant to clear chips and dust from the tap.

Grinding

Diamond, silicon carbide or aluminium oxide grinding wheels can be used.

Polishing

Start with loose 400-grit silicon carbide on a steel wheel. For the final polish, use cerium oxide or alumina on a polishing pad for glass or ceramics. A 0.5%uFFFDin. (0.013%uFFFDm) finish can be achieved.

Composition

Macor MGC is a white, odourless, porcelain-like (in appearance) material composed of approximately 55% fluorophlogopite mica and 45% borosilicate glass. It has no known toxic effects: however the dust created in machining can be an irritant. Good housekeeping and appropriate machining techniques can avoid this irritation. The material contains the following compounds:

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