mechanical engineering

Carbon steels

Their use is restricted to the cutting of soft metals and wood. Performance is poor above 250°C.

High-speed Steels

These are used extensively, particularly for multi-point tools. They have been replaced to a large extent by carbides for single-point tools. Their main application
is for form tools and complex shapes, e.g. for gearcutting and broaching. They are also used for twist drills, reamers, etc.

Carbides

These consist of powdered carbides of tungsten, titanium, tantalum, niobium, etc., with powdered cobalt as binder. They are produced by pressing the powder
in dies and sintering at high temperature. They are then ground to the final shape. They are generally used as tips and can operate up to 1oo0"C.

Laminated carbide

These consist of a hard thin layer of titanium carbide bonded to a tungsten carbide body. The surface has very high strength at high temperature, whilst the body has high thermal conductivity and thus efficient removal of heat.

Diamonds

These are the hardest of all cutting materials with low thermal expansion and good conductivity. They are twice as good as carbides under compression. A good finish can be obtained with non-ferrous metals and final polishing can be eliminated. Diamonds are particularly good for cutting aluminium and magnesium alloys, copper, brass and zinc. They have a long life.