English
EspañaWhen using mechanical anchors, words such as 5.8 and 8.8 are often heard. So, what do these levels mean?
According to the provisions of GB/T3098.1-2000, the performance equivalent grades of mechanical anchors are 4.8, 5.8, 6.8, 8.8, 10.9, and 12.9, and the commonly used grades are 5.8 and 8.8. What do these levels mean? How to choose?
6.8 level means: the standard value of tensile strength is 600MPa, and the standard value of yield strength is 480MPa. Because the elongation rate does not meet the 8% requirement in the steel structure design code.
It is generally not recommended to use high-strength bolts of grade 10.9 and 12.9, because the high-strength bolts themselves have higher hardness after heat treatment, and the later surface anti-corrosion treatment increases the probability of hydrogen embrittlement.
8.8 level means: the standard value of tensile strength is 800MPa, and the standard value of yield strength is 640MPa. The use of mechanical anchor bolts under this strength is also cost-effective.
According to the provisions of GB/T3098.1-2000, the performance equivalent grades of mechanical anchors are 4.8, 5.8, 6.8, 8.8, 10.9, and 12.9, and the commonly used grades are 5.8 and 8.8. What do these levels mean? How to choose?
6.8 level means: the standard value of tensile strength is 600MPa, and the standard value of yield strength is 480MPa. Because the elongation rate does not meet the 8% requirement in the steel structure design code.
It is generally not recommended to use high-strength bolts of grade 10.9 and 12.9, because the high-strength bolts themselves have higher hardness after heat treatment, and the later surface anti-corrosion treatment increases the probability of hydrogen embrittlement.
8.8 level means: the standard value of tensile strength is 800MPa, and the standard value of yield strength is 640MPa. The use of mechanical anchor bolts under this strength is also cost-effective.
