5/8-11 ASTM A563 DH HVY NUT HDG .020” ASTM A563 DH HEAVY HEX NUT HDG ASME/ANSI B18.2.2 1987 IFI-7 AF 1.031 – 1.062” THK 0.587 – 0.631” TAPPED OVER SIZE PER ASTM A 153 CLASS C, WAXED & LUBRICATED