5/16"-18 Grade 2 Zinc Finish NTE Steel Jam Nylon Insert Lock Nut / THREAD DIRECTION: RIGHT-HAND NUT HEIGHT: 0.265 INCHES NOMINAL END ITEM IDENTIFICATION: 2320-01-531-2701;TRUCK,UTILITY-INTERNALLY TRANSPORTABLE WIDTH ACROSS FLATS: 0.500 INCHES NOMINAL THREAD SERIES: UNC THREAD QUANTITY PER INCH: 18 NOMINAL THREAD SIZE: 0.312 INCHES THREAD TOLERANCE CLASS: 2B INTERNAL PART NAME ASSIGNED BY CONTROLLING AGENCY: NUT,JAM,NYLON INSERT MATERIAL: PLASTIC NYLON LOCKING INSERT MATERIAL: STEEL NUT SURFACE TREATMENT: ZINC OVERALL EXCEPT INSERT