The material of this product is all 42 chromium molybdenum, with a mechanical property level of 12.9 (hardness: HRC39-44) Performance level 12.9 high-strength screws, made of materials that have undergone heat treatment, can achieve: 1: The nominal tensile strength of bolt material reaches 1200MPa level 2: The yield strength ratio of bolt material is 0.9 3: The nominal yield strength of bolt material reaches 1200 0.9=1080MPa level VS Performance grade 10.9 bolts, after heat treatment, can achieve: 1: The nominal tensile strength of bolt material reaches 1000MPa level 2: The yield strength ratio of bolt material is 0.9 3: The nominal yield strength of bolt material reaches 1000 0.9=900MPa level Package Included: 4Pcs 12.9 Wheel Alignment Camber Bolts