There are different cutting processes done on varying conditions. Depending on the cutting conditions and the requirements of the respective cutting tool, it is important that they are of the right properties. The type of material selected for a specific application depends on what is being machined. Here is a classification of these materials.

 

Carbon Tool Steel

 

This is one of the inexpensive metal cutting tools common in low-speed machining operations. These carbon steel cutting tools are constructed with a composition of 0.6%-1.5% carbon and small amounts, less than 0.5%, of Si and Mn. To enhance the hardness, other materials such as V and Cr could also be added.

 

Carbon tool steels are preferred because they are abrasion resistant and can maintain the cutting edge for a long period. However, they lose their hardness when temperatures reach 250 °C. This means that they are not good for high-temperature operations.

 

Common applications that use carbon steel tool include milling tools, twist drills, and forming tools.

 

High-Speed Steel (HSS)

 

This is another high carbon steel featuring a significant quantity of alloys like chromium and tungsten to increase their hardness and wear resistance. HSS loses its hardness when temperatures hit 650 °C. It is, therefore, advisable to use coolants to increase tool life. The following surface treatment is also used on HSS to improve the properties.

 

• Super-finishing to lower friction
• Chromium electroplating to lower friction
• Nitriding to increase wear resistance
• Oxidation to reduce friction

 

High-speed steel tools are common in broaches, single point lathe tools, and milling cutters.

 

Cemented Carbide and Cement

 

The cemented carbide cutting tool is created using metallurgy method. It is made from tungsten, titanium carbide and tantalum with cobalt as a binder. The most notable thing about the cemented carbide tools is that they are very hard and can be used for cutting at high speed and temperatures. For example, you can use them for cutting at temperatures of 1000 °C without losing their properties.

 

For rough cuts, it is better to use high cobalt tool while low combat tools are ideal for finishing applications.

 

Ceramics

 

The common ceramic materials used in cutting tools are silicon nitride and aluminum oxide. When the ceramic material powder is compacted and inserted at very high temperatures, the resulting tools are inert and resistant to corrosion. Therefore, they have high compressive strength.

 

The ceramics are stable when operating even in temperatures of up to 1800°C and are about 10 times faster than HSS. Because the friction between the chip and surface is low and heat conductivity is also low, you do not need an additional coolant.

 

Cubic Boron Nitride (CBN)

 

CBN is the second hardest material and is commonly used in hand machines. They provide high abrasion resistance and utilize abrasive in grinding wheels. They are ideal at speeds of 600-800m/min.

 

Diamond

 

This is the hardest material used in tools. It features a high melting point and thermal conductivity. Therefore, it provides excellent abrasion resistance, low thermal expansion, and low friction coefficient. It is considered ideal for machining hard materials like glass, nitrides, and carbides. Note that diamond is not ideal for machining steel.

 

This post brings you the main cutting tools materials and their properties to help you pick the ideal option for your facility.