1/4" Zinc Finish External Tooth Lock Washer / HOLE DIAMETER: 0.256 INCHES MINIMUM AND 0.267 INCHES MAXIMUM OUTSIDE DIAMETER: 0.494 INCHES MINIMUM AND 0.510 INCHES MAXIMUM MATERIAL THICKNESS: 0.023 INCHES MINIMUM AND 0.028 INCHES MAXIMUM END ITEM IDENTIFICATION: TOW TRACTOR, AIRCRAFT; TRANSMISSION ASSY; ASSEMBLY, DRIVE SHAFT; TOW TRACTOR, A/C (P/N 4JPAV, PCC: 6J9) PART NAME ASSIGNED BY CONTROLLING AGENCY: 1/4, EXTERNAL TOOTH LOCK WASHER, ZINC PLATED MATERIAL: STEEL OVERALL MATERIAL DOCUMENT AND CLASSIFICATION: SAE J403 1050-1065 ASSN STD SINGLE MATERIAL RESPONSE OVERALL SURFACE TREATMENT: ZINC OVERALL SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: ASTM B633, SC1. TYPE 111 AND BAKE ASSN STD SINGLE TREATMENT RESPONSE OVERALL STYLE DESIGNATOR: 100 FLAT EXTERNAL TEETH