Stainless steel bolt material grades, come and get new knowledge

The material classification of stainless steel bolts includes austenitic stainless steel, ferritic stainless steel, martensitic stainless steel, and precipitation hardened stainless steel. The selection of stainless steel screws also has principles. From what aspects, you can choose the stainless steel screws you need.

1. Ferritic stainless steel

  Type 430 ordinary chromium steel has better corrosion resistance and heat resistance than type 410 and is magnetic, but it cannot be strengthened by heat treatment. It is suitable for stainless steel screws with slightly higher corrosion and heat resistance and general strength requirements.

  2. Martensitic stainless steel

  Type 410 and 416 can be heat-treated and strengthened, with a hardness of 35~45HRC and good machinability, and are used for general-purpose heat-resistant and corrosion-resistant stainless steel screws. Type 416 has a slightly higher sulfur content and is a free-cutting stainless steel. Type 420, with a sulfur content of R0.15%, has improved mechanical properties and can be heat-treated and strengthened, with a maximum hardness of 53~58HRC, and is used for stainless steel screws that require higher strength.

  3. Precipitation Hardening Stainless Steel

  17-4PH, PH15-7Mo, they can obtain higher strength than the usual 18-8 type stainless steel, so they are used for high-strength, corrosion-resistant stainless steel screws.

  A-286, a non-standard stainless steel, has higher corrosion resistance than the commonly used 18-8 stainless steel, and still has good mechanical properties at elevated temperatures. It is used as a high-strength, heat-resistant, corrosion-resistant stainless steel screw and can be used up to 650~700℃.

  4. Austenitic stainless steel

  The commonly used grades are 302, 303, 304, and 305, which are the so-called "18-8" austenitic stainless steel grades. They are similar in terms of corrosion resistance and mechanical properties. The starting point for selection is the production process of stainless steel screws, which in turn depends on the size and shape of the stainless steel screws, as well as the production quantity.