1/4"-20 Zinc Finish Steel with External Tooth Lockwasher K-Lock Nut / THREAD CLASS: 2B THREAD DIRECTION: RIGHT-HAND LOCKING FEATURE: PREVAILING TORQUE ALL METAL DESIGN WASHER OUTSIDE DIAMETER: 0.494 INCHES MINIMUM AND 0.506 INCHES MAXIMUM OVERALL HEIGHT: 0.178 INCHES MINIMUM AND 0.193 INCHES MAXIMUM NUT STYLE: A294 HEXAGON END ITEM IDENTIFICATION: 4120-01-585-1564 WIDTH ACROSS FLATS: 0.423 INCHES MINIMUM AND 0.438 INCHES MAXIMUM THREAD SERIES: UNC THREAD QUANTITY PER INCH: 20 NOMINAL THREAD SIZE: 0.250 INCHES PART NAME ASSIGNED BY CONTROLLING AGENCY: 1/4"-20 ZINC FINISH GRADE KEPS LOCK NUT WITH EXTERNAL TOOTH LOCKWASHER MATERIAL: STEEL NUT MATERIAL: STEEL COMP 1050 WASHER MATERIAL DOCUMENT AND CLASSIFICATION: LOW CARBON STEEL MFR REF SINGLE MATERIAL RESPONSE NUT MATERIAL DOCUMENT AND CLASSIFICATION: AISI 1050 OR EQUIVALENT MEDIUM CARBON STEEL ASSN STD SINGLE MATERIAL RESPONSE WASHER SURFACE TREATMENT: ZINC OVERALL SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: FE/ZN 3AT PER ASTM F1941 ASSN STD SINGLE TREATMENT RESPONSE OVERALL