1/4-20 Case Hardened Zinc Plated Serrated Large Hex Flange Nut / THREAD CLASS: 1B THREAD DIRECTION: RIGHT-HAND NUT STYLE: A294 HEXAGON END ITEM IDENTIFICATION: 4310-01-582-0571; MRAP BUFFALO MK2A2 WIDTH ACROSS FLATS: 0.438 INCHES NOMINAL THREAD SERIES: UNC THREAD QUANTITY PER INCH: 20 NOMINAL THREAD SIZE: 0.250 INCHES MATERIAL: STEEL OVERALL SURFACE TREATMENT: ZINC OVERALL