1 1/4"-5 ACME Plain Finish Heavy Hex Nut / THREAD CLASS: 2G NUT STYLE: A12 HEXAGON END ITEM IDENTIFICATION: 5180-01-477-2390 WIDTH ACROSS FLATS: 2.00 INCHES NOMINAL THREAD SERIES: ACME THREAD QUANTITY PER INCH: 5 NOMINAL THREAD SIZE: 1.25 INCHES PART NAME ASSIGNED BY CONTROLLING AGENCY: NUT SURFACE TREATMENT: PHOSPHATE MANGANESE OVERALL SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: MIL-DTL-16232,CLASS 2 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL