1/2-13 REGULAR SQUARE NUT HDG .015” SAE J995 GRADE 2 SQUARE NUT H.D.G. ASME/ANSI B18.2.2 1987 IFI-7AF 0.788-0.812” AC 1.052-1.149” TH 0.418-0.458” Tapped Over Size per ASTM A 153 class C