The JIS SUS440C martensitic stainless steel contains 0.95wt%- 1.20wt% carbon and 16wt%- 18wt% chromium. Due to higher quantity of carbon and chromium, the SUS440C is excellent in both corrosion and wear resistance which has been widely applied to bearing The JIS SUS440C martensitic stainless steel contains 0.95wt%- 1.20wt% carbon and 16wt%- 18wt% chromium. Due to higher quantity of carbon and chromium, the SUS440C is excellent in both corrosion and wear resistance which has been widely applied to bearing