What are the types of High-Speed Steel Cutting Tools

High-speed steel (HSS) tools are high-hardness, high-temperature resistant cutting tools widely used in metalworking, including the manufacturing of automotive transmission systems. The main types and characteristics are as follows:

1. General-Purpose High-Speed Steel Tools: Such as T1 (tungsten-based) and M2 (molybdenum-based), these are the basic materials for traditional HSS tools, offering good toughness and wear resistance. They are suitable for low to medium-speed cutting, such as lathe tools, milling cutters, and drill bits.
2. Cobalt High-Speed Steel Tools: Such as M35 and M42, the addition of cobalt enhances red hardness (high-temperature hardness), making them suitable for high-speed cutting and machining high-hardness materials, such as bearing races or gears, with significantly improved durability.
3. Vanadium High-Speed Steel Tools: Such as M4, containing a higher amount of vanadium, which increases wear resistance and resistance to chipping. They are suitable for interrupted cutting or machining difficult-to-machine materials like stainless steel.
4. Powder Metallurgy High-Speed Steel Tools: Manufactured using powder metallurgy processes (such as PM M4), these tools have fine grains and good uniformity, combining high toughness and wear resistance. They are often used for precision machining and complex workpieces.

These tools are used in automotive transmission systems for machining components such as gears, shafts, and races. The advantages of HSS tools are their lower cost, ease of grinding and re-grinding, and suitability for various cutting conditions. However, their heat resistance is limited (typically 600-650°C), and they may not be as effective as CBN or ceramic tools in ultra-high-speed or hard turning applications. Coating technologies (such as TiN coating) can further enhance their performance and extend their service life. Selection should be optimized based on workpiece material and cutting parameters, such as cutting speed and feed rate, to balance efficiency and tool wear, thereby ensuring the high precision and reliability of transmission components.