SUS420 is a martensitic stainless steel specified in the Japanese JIS standard. It features high hardness, wear resistance, and corrosion resistance (especially in freshwater and mildly corrosive environments). Heat treatment imparts excellent mechanical properties, making it widely used in CNC machining. The following is a categorized description of its specific application scenarios:
Cutting Tools and Molds
- Cutting Tool Manufacturing:
After quenching and tempering, SUS420 can reach a hardness of HRC50-55 and offers excellent wear resistance. It is commonly used in the production of small and medium-sized cutting tools, such as food processing knives (coffee burrs, slicers, and boning knives) and woodworking tools (engraving knives and milling cutters). CNC machining allows for precise control of the cutting edge angle and dimensional accuracy, ensuring stable cutting performance.
- Mold Accessories:
This material is suitable for mold parts requiring high wear and corrosion resistance, such as cores and inserts for plastic molds, and guide pins and locating pins for cold-work molds. CNC milling and grinding processes ensure the precise fit of mold components and extend mold life.
Medical Devices
- Surgical Instruments:
SUS420's corrosion resistance (especially in environments with alcohol and disinfectants) and high strength make it suitable for instruments such as surgical scissors, hemostats, and scalpel handles. CNC turning and drilling processes enable precision machining of complex shapes, meeting the stringent surface finish (to prevent bacterial growth) and dimensional accuracy requirements of medical devices.
- Medical Device Components:
Rotating components in dental handpieces and valve components in infusion equipment, for example, require stability during repeated use and sterilization. The processing and mechanical properties of SUS420 meet these requirements.
Machinery and Automotive Components
- Precision Shaft Parts:
Used in drive shafts and gear shafts requiring wear and impact resistance, CNC machining (such as external cylindrical grinding and threading) ensures shaft roundness, cylindricity, and fitting tolerances, reducing wear and vibration during operation. - Valve and Pump Parts:
Such as valve cores and seats for small and medium-sized valves, and impeller shafts for water pumps. SUS420's corrosion and wear resistance withstands long-term erosion from media such as water and oil. CNC boring and milling ensure the precision of sealing surfaces, preventing leaks.
- Automotive Parts:
Fuel injection components for automotive engines and precision parts for brake systems (such as brake pad pins) must withstand high temperatures and friction. The high precision of CNC machining ensures stable interoperability with other components.
Security and Hardware Products
- Lock Core Components:
Such as the pins and bolts in lock cylinders require high-precision dimensional fit and wear resistance. CNC wire cutting and EDM processes can achieve complex grooves and special shapes, enhancing lock security.
- Hardware Tools:
Such as wrenches and screwdriver bits, and the movement components of tape measures. SUS420 achieves high hardness after heat treatment. CNC stamping and milling processes enable mass production with guaranteed consistency.
Other Special Applications
- Food Industry Equipment:
Components such as food mixer blades and conveyor chain pins must withstand cleaning and food contact. SUS420's corrosion resistance and ease of machining make it a suitable choice. CNC machining ensures a smooth surface without blind spots, meeting food hygiene standards.
- Marine and Outdoor Equipment:
Fishing gear accessories used in freshwater environments (such as hooks and reel components) and bracket connectors for outdoor lighting fixtures resist corrosion in humid environments. The precision of CNC machining ensures reliable component assembly.
Summary
The key to SUS420's CNC machining applications lies in its combination of heat-treatable hardening (hardness increased through quenching and tempering) and moderate corrosion resistance combined with high wear resistance. It is particularly suitable for parts requiring precise fit, repeated use, and exposure to moderate friction or mildly corrosive environments. CNC machining technologies (such as CNC turning, milling, grinding, and wire cutting) further leverage the material's properties to meet the precision, surface quality, and structural complexity requirements of various applications.