Features Serrated flange locknut allows full thread surface contact for large load-bearing strength, plus vibration and impact resistance. Meets IFI 100/107 standards. Nut Style / Top Lock Flange Nut System of Measurement / Inch Basic Material / Steel Fastener Finish / Zinc Plated Fastener Thread Direction / Right Hand Fastener Thread Type / UNC (Coarse) Dia./Thread Size / 1/2"-13 Material Grade / Grade 2 Width Across Flats / 3/4 in Nut Height / 29/64 in Flange Dia. / 1 1/32 in