High-strength bolts are bolts grade 8.8 and above bo […]
High-strength bolts are bolts grade 8.8 and above bolts, 9.8 high-strength bolts, and 10.9, 12.9 are high-strength bolts.
With the bolt performance grade points 3.6,4.6,4.8,5.6,6.8,8.8,9.8,10.9,12.9 and so on more than 10 grades, of which 8.8 and above bolts, made of low carbon alloy steel or medium carbon steel and heat treatment (quenching , Tempering), commonly known as high-strength bolts, the rest known as ordinary bolts.
The bolt performance grade label consists of two parts, representing the nominal tensile strength and yield ratio of the bolt material, respectively. Such as 10.9, 10 indicates that the tensile strength of the bolt is 1000MPa, 0.9 means that the yield ratio of the bolt is 0.9, that is to say the ratio of the yield strength and the tensile strength of the bolt is 0.9, that is, the yield strength of the bolt is 1000 * 0.9 = 900MPa, that is, when the actual use of the bolt cross-section normal stress must be less than 900MPa.