Hexagon bolt grade. Bolt performance grades are divided into many grades, like ordinary bolts are 3.6, 4.6, 4.8, 5.6, 6.8, high-strength bolts are 8.8, 9.8, 10.9, 12.9, and bolts of 8.8 and above are made of low-carbon alloy steel or medium-carbon steel, and are heat-treated (quenched, tempered) Fire), commonly known as high-strength bolts, and ...
Get Price