HEXAGON HEAD BOLTS With Hexagon Nut DIN 7990 Steel Grades: 4.6, 5.6, 8.8• Finish: Self, Black, Bright Zinc, Hot Dip Galvanized Dimensions d M12 M16 M20 M22 M24 M27 M30 P 1.75 2 2.5 2.5 3 3 3.5 b 19.5 23 26 58 29.5 32.5 35 k 8 10 13 14 15 17 19 m 10 13. https://www.kova.in/technical-information/din7990/