The largest material group in the range of metal cutting is steel, covering nonalloy materials, high alloy materials, cast iron, ferritic and martensitic stainless steel. Steel usually has good machinability, but the details will be different because of the different carbon content and material hardness.
Stainless steel is an alloy material with a chromium content of more than 12%; other types of alloys may include elements such as molybdenum and chromium. Different ferrite, martensite, austenite and duplex (austenite ferrite) form a large series of materials. All these materials have one thing in common: a lot of heat will be produced on the cutting edge of the cutting tool during machining and groove wear and chip accretion will easily occur.
Contrary to steel, cast iron is a short chip type material. Gray cast iron (GCI) and malleable cast iron (MCI) are very easy to process, while nodular cast iron (NCI), vermicular cast iron (CGI) and austenitic cast iron (ADI) are relatively difficult to process. All cast iron containing SiC will cause great abrasive wear to the cutting edge.
Nonferrous metals are softer metals such as aluminum, copper, brass, etc. Aluminum with 13% silicon content has strong abrasive wear. Generally, for the blade with sharp cutting edge, high cutting speed and long tool life can be expected.
Heat resistant premium alloys include many high alloy iron, nickel, cobalt, and titanium-based materials. They are sticky and produce swarf, work hardening and a lot of heat. This kind of material is very similar to the ISO m range, but it is more difficult to cut, and it will reduce the cutting edge life of the cutter.
This group includes steel with a hardness between HRC 45-65 and chilled cast iron with a hardness of about HB 400-600. Because of the hardness, this group of materials are not easy to process. In the process of cutting, it will produce a lot of heat, and it has a great abrasivity to the cutting edge.