Panel and Enclosure Shoulder Washers: Type - Shoulder Washer/Bushing; Material - Nylon; Screw Size - 1/4"; Screw Hole I.D. - 0.260" (6.6 mm); Length Under Flange - 0.250" (6.4 mm); Diameter Under Flange - 0.312" (7.9 mm); Flange Thickness - 0.065" (1.7 mm); Washer O.D. - 0.513" (13mm); Material Specification - Nylon, Grade 6/6