Cutting Tool Materials

 The principal cutting tool materials are:

1.    Plain Carbon steel
2.    Medium alloy steel
3.    High speed steel
4.    Stellite
5.    Cemented carbide
6.    Ceramics
7.    Diamond
8.    Abrasives

Plain Carbon steel

Carbon steels cannot withstand its hardness above 2000C. So they are used for hand operated tools like files, saws and scrapers.

Medium Alloy steel

Alloying elements like chromium, vanadium, tungsten etc. are added to the high carbon steels to improve properties like hardness, wear resistance, toughness etc. This type of steels are used for hand operated tools like chisel, saw, scraper etc.

High speed steel (HSS)

High speed steels with alloying elements like tungsten, vanadium, cobalt etc. are used in hardened condition as a good general purpose tool material in machining like turning, shaping, drilling, planing etc. They can withstand hardness upto cutting temperature of 9000C and can operate 2 to 3 times speed higher than plain carbon steels.

Stellite

Stellite is the trade name of a non ferrous cast alloy tool material composed of cobalt, chromium and tungsten. They can withstand hardness upto 10000C and can operate at 2 times the speed than HSS.

As this material is too brittle they are not used in metal cutting operations and extensively used in non metal cutting applications such as rubber and plastics.

Cemented Carbide

Cemented carbide with tungsten carbide, titanium carbide and cobalt is the hardest manufactured material and has extremely high compressive strength. It is manufactured in the form of tips of various shapes and can operate more than 6 times speed higher than HSS. Now a days Cemented carbide tipped tools are widely used in production and manufacturing.

Ceramics

It is aluminium oxide material made in the form of tips. Ceramic tipped tools can operate at a cutting speed 4 times higher than that of cemented carbides, but cannot be used for tools operating in interrepted cuts and vibration as well as for removing heavy chips.

Diamond

The diamond is the hardest known material and can be run at cutting speed 50 times more than that of HSS and at temperature upto 16500C. Diamond is suitable for cutting very hard materials such as glass, ceramics and other abrasive materials.

Abrasives

Abrasive grains in various forms-loose, bonded into wheels and stones and embedded in papers and cloth find wide application in industry for finishing operations like grinding and polishing.