Item No.: SGE5PW~SGE30PWInner Race: 440C Stainless steel,heat treated,precision ground. Outer Race: 304 Stainless steel,with liner of PTFE composite. Sliding contact surfaces: Steel/PTFE composite.Phone: +86-592-580 8851 / +86-592-580 7618Email: sales@ldk-bearing.com ; benjamin@ldk-bearings.com