304 / 316L (Austenitic Stainless Steel)

Physical & mechanical properties:

Outstanding resistance to rust, acid, alkali and moisture. 316L performs better against chloride ion, seawater and chemical media. High toughness and ductility, non-magnetic, cannot be hardened by conventional heat treatment.

Machinability:

High material ductility, easy to form built-up edge and cause tool sticking. Special cutting tools and reduced cutting parameters are required. Excellent grinding performance for ultra-precision machining.

Dimensional stability:

Minimal machining deformation, excellent stability, stably reaches ±0.005 mm ultra-precision.

Surface treatment:

Polishing, wire drawing and passivation. Additional anti-rust treatment is generally unnecessary.

Applications:

Food equipment, medical devices, chemical industry, fluid valve cores, valve bodies, anti-corrosion shafts and precision structural parts.

Advantages & Disadvantages:

Advantages: Superior corrosion resistance, high sanitary standard, stable precision.

Disadvantages: Difficult to machine, high tool wear, relatively high material cost.

416 / 420 (Free-cutting Martensitic Stainless Steel)

Physical & mechanical properties:

Can be quenched to improve hardness and wear resistance with high overall strength. Inferior anti-rust performance compared with 304/316L.

Machinability:

Smooth cutting performance similar to carbon steel, ideal for mass production of precision parts.

Applications:

Instrument shafts, precision pins, small rotational components.