Cutting Tool Material Selection Guide for Different Machining Applications
Selecting the right cutting tool material is critical for machining efficiency, tool life, surface finish quality, and overall production cost. Different cutting applications require different combinations of hardness, wear resistance, toughness, heat resistance, and chemical stability. The wrong tool material can lead to rapid wear, poor dimensional accuracy, unstable cutting performance, and increased machining cost.
Tool materials used in machining must have high hot hardness, strong wear resistance, sufficient bending strength, impact toughness, and good chemical inertness. In addition, they should offer good machinability during manufacturing processes such as forging, cutting, and heat treatment, while maintaining dimensional stability during use.
Main Performance Requirements for Cutting Tool Materials
In general, materials with higher hardness also provide better wear resistance. However, as hardness increases, bending strength and impact toughness often decrease. This means there is always a balance between hardness and toughness when selecting cutting tool materials.
For example, high hardness is important for maintaining cutting edge stability and wear resistance, especially during high-speed machining or when processing hard materials. However, tools with insufficient toughness may chip or break under interrupted cutting conditions or heavy cutting loads.
Common Types of Cutting Tool Materials
Cutting tool materials are generally divided into several major categories, including high speed steel, cemented carbide, cermet, ceramic, polycrystalline cubic boron nitride, and polycrystalline diamond.
High speed steel remains one of the most widely used tool materials because it offers a good balance of toughness, bending strength, impact resistance, and processability. It is especially suitable for tools such as drills, taps, reamers, and complex cutting tools that require good toughness and easier regrinding.
Cemented carbide is widely used for CNC machining because of its higher hardness and wear resistance compared with high speed steel. It is suitable for general metal cutting, high-speed machining, and large-volume production.
Cermet and ceramic tools are commonly used when higher cutting speeds, better surface finish, and improved heat resistance are required. However, these materials are more brittle and are generally less suitable for interrupted cutting or heavy impact conditions.
Special Tool Materials for High Hardness and Non-Ferrous Materials
Polycrystalline cubic boron nitride, commonly known as PCBN, is suitable for machining hardened steel, hard cast iron, and other high-hardness materials. It offers excellent wear resistance and can maintain cutting performance under high temperature conditions.
Polycrystalline diamond, or PCD, is mainly used for machining non-ferrous metals, aluminum alloys, copper alloys, plastics, composites, carbon fiber materials, and glass fiber reinforced plastics. Because diamond reacts with iron at high temperatures, it is generally not used for machining ferrous metals.
Traditional carbon tool steel and alloy tool steel are now mainly used for simpler cutting tools such as dies, hand tools, taps, and low-speed cutting applications where high hardness and heat resistance are less critical.
How to Choose the Right Tool Material
The selection of cutting tool material depends on the workpiece material, machining speed, cutting condition, required surface finish, tool geometry, and production volume. Choosing the right balance between hardness, wear resistance, and toughness can help improve machining efficiency, extend tool life, and reduce manufacturing cost.
For demanding machining projects, tool material selection should always be reviewed together with cutting parameters, coolant conditions, and machine rigidity to achieve the best overall machining performance.