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440 Stainless Steel

440 Stainless Steel Grade (UNS S44000)

440 stainless steel grade possessed high carbon content and equipped with the highest hardness perfect for ball bearings and valve components.

440 Stainless Steel440 stainless steel, known as UNS S44000, is a type high carbon steel with the highest hardness, strength, and wear resistance. Their obtained mechanical properties are improved by heat treatment. Such remarkable properties are suitable for applications such as ball bearings and valve components.

440 Stainless Steel grade has three common forms including: 440A, 440B, & 440C. 440A has a lower percentage of carbon content but both 440A and 440B almost have the same mechanical properties. 440C is more readily available than other standard stainless steel grades. These martensitic stainless steel grades are high hardness steels, fabricated with the use of techniques requiring tempering and hardening treatments.

440 martensitic stainless steel grades exhibit lower corrosion resistance compared to other austenitic steel grades. The loss of strength and loss of ductility which is caused by over-tempering at highly severe temperatures limit their application.

440 grade stainless demonstrates better resistance against alkalis, freshwater, mild acids, foods, and air. If granted with a smoothly polished surface, 440 can also resist corrosion in passivated, tempered, and hardened conditions. This grade exhibit corrosion resistance same to that of 304 stainless steel grades.

440 steel can be applied in a wide variety of applications such as the following:

  • Surgical equipment
  • Valve seats
  • High-quality knife blades
  • Chisels
  • Rolling element bearings

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