440A stainless steel 440A Name: martensitic stainless steel Standard: AISI, ASTM Type: 440A UNS Number: S44002 ● 440A features and applications: 440A stainless steel hardened and excellent performance, high hardness, compared with 440B and 440C steel steel with high toughness. Used as cutting tools, measuring tools, bearings. ● 440A chemical composition ①: C C: 0.60 ~ 0.75 Manganese Mn: ≤ 1.00 Si Si: ≤ 1.00 Chromium Cr: 16.0 ~ 18.0 Ni-Ni ②: - Phosphorus P: ≤ 0.04 S S: ≤ 0.03 Mo Mo: ≤ 0.75 Note: ① single value, unless otherwise stated herein, are the highest value; ② process for certain pipe, some models of the nickel content of austenitic stainless steel to be slightly higher than the values ??shown in the table; ③ free; ④ Ta containing the highest amount of 0.10%; ⑤ highest content of 0.75%; ⑥ highest content of 0.70% 440A-440B-440C carbon content and hardness of the successive increases by the ABC (A-0.75%, B-0.9%, C-1.2% ). 440C is an excellent high-end stainless steel, the hardness is usually reached 56-58RC. This three resist rust are good, 440A best, and 440C the least. 440C with the very common. Martensitic stainless steel's chemical composition is characterized in the 0.1% -1.0% C, 12% -27% Cr based on the combination of different ingredients to add molybdenum, tungsten, vanadium, and niobium and other elements. As the organizational structure for the body-centered cubic structure, and therefore a sharp decline in strength at high temperatures. In the 600 ℃, high temperature strength in the highest types of stainless steel, creep strength is also highest. 440A hardened excellent performance, high hardness, compared with 440B and 440C steel steel with high toughness. 440B for cutting tools, measuring tools, bearings and valves, compared with 440A steel, high hardness, high toughness over 440C steel. 440C has all stainless steel, heat-resistant steel in the highest hardness for the nozzles, bearings. 440F 440C is to improve the performance of steel-cutting steel for auto lathe