螺栓性能等级的含义（The meaning of bolt performance grade）.doc

螺栓性能等级的含义（The meaning of bolt performance grade） The meaning of bolt performance grade Steel structure connecting bolts 3.6, 4.6, performance grade 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, 12.9 and more than 10 levels, of which 8.8 or more bolt material for low carbon alloy steel or carbon steel by heat treatment (quenching and tempering), known as the high strength bolts, known as the rest ordinary bolt. There are two parts in the performance grade of bolts. They are the nominal tensile strength of the bolt material and the ratio of the tensile strength. For example, a performance grade 4.6 bolt means yes: 1. Nominal tensile strength of bolt material reaches 400MPa grade; 2, the bolt strength ratio is 0.6; 3. The nominal yield strength of bolt material is 400 * 0.6=240MPa class, and the performance grade 10.9 is high strength bolt. The material can be reached after heat treatment: 1. Nominal tensile strength of bolt material reaches 1000MPa grade; 2, the bolt strength ratio is 0.9; 3. The nominal yield strength of bolt material is 1000 * 0.9=900MPa class The meaning of the performance grade of a bolt is an international standard. The performance of the bolt of the same performance grade is the same regardless of the material and the place of origin. The performance grade can only be used in the design. Strength class, class 8.8 and 10.9 The shear stress grades of bolts are 8.8GPa and 10.9Gpa 8.8 nominal tensile strength 800N/MM2 nominal yield strength 640N/MM2 The general bolt is expressed with the strength of X.Y, X*100= tensile strength of this bolt, X*100* (Y/10) = yield strength of this bolt (as specified by the mark: yield strength / tensile strength =Y/10) =============== Class 4.8 Of this bolt Tensile strength: 400MPa The yield strength is 400*8/10=320MPa Desolate Another: stainless steel bolts are usually labeled A4-70, A2-70 look, meaning otherwise explained measure There are two main types of one of the worlds length measuring unit, a metric unit of measure for the