Stainless Steel, Arbor Shim, Grade 18-8, Shim Thickness 0.005 in/ OUTSIDE DIAMETER: 0.834 INCHES MINIMUM AND 0.854 INCHES MAXIMUM APERTURE DIAMETER: 0.641 INCHES MINIMUM AND 0.649 INCHES MAXIMUM OVERALL THICKNESS: 0.0008 INCHES MINIMUM AND 0.0011 INCHES MAXIMUM CONSTRUCTION: ONE-PIECE HARDNESS RATING: 80.0 ROCKWELL B MINIMUM PART NAME ASSIGNED BY CONTROLLING AGENCY: SHIM, ROUND MATERIAL: STEEL CORROSION RESISTING STYLE DESIGNATOR: A1 CIRCULAR