4X8X.5 Hardened Spring Steel DIN 988 Precision Shim Ring / CROSS-SECTIONAL SHAPE STYLE: 2 BLANK RECTANGULAR HOLE DIAMETER: 4.3 MILLIMETERS NOMINAL PERIPHERAL SHAPE STYLE: 1 ROUND CENTER HOLE SHAPE STYLE: 1 ROUND THICKNESS: 0.5 MILLIMETERS NOMINAL OVERALL DIAMETER: 8.0 MILLIMETERS NOMINAL PART NAME ASSIGNED BY CONTROLLING AGENCY: WASH, FLT SPECIAL FEATURES: FINISH: PL20, TYPE 1, GRADE 1, CLASS A OR B PER FM100 MATERIAL: STEEL OVERALL