ASTM/ASME 440F Stainless Steel Pipes & Tubes are free-machining martensitic (UNS S44020) products conforming to ASTM A213/A268 standards, featuring a sulfur-enhanced (0.15% min.) high-carbon (0.95-1.20%) chromium (16-18%) composition that combines the extreme hardness of 440C stainless (up to 62 HRC when heat-treated) with improved machinability for precision bearing components and cutting tools. This specialty grade maintains the exceptional wear resistance of 440-series alloys while achieving superior chip formation and surface finish in CNC operations, though with some reduction in transverse mechanical properties. Primarily utilized for high-performance machined parts rather than pressure applications, 440F stainless steel tubes serve critical roles in aerospace mechanisms, surgical instrument manufacturing, and precision bearing systems where complex geometries demand both ultra-high hardness (Rc 54-60 typical service range) and production efficiency, requiring careful post-machining heat treatment to optimize corrosion resistance and dimensional stability in demanding service environments.