High-strength Friction Grip Bolt, English literal translation: High Strength Friction pre-tightening Bolt, English abbreviation: HSFG. It can be seen that the high strength bolt mentioned in Chinese construction is the abbreviation of the high strength friction pretightening bolt.
The core difference between high-strength bolts and ordinary bolts is not the strength of the material used, but the form of force. The essence is whether to apply preload and use static friction force to resist shear.
In fact, in the British standard specification, the American standard specification mentioned in the high strength BOLT (HSFG BOLT) only 8.8 and 10.9 class two (BS EN 14399 / ASTM-A325&ASTM-490), while the ordinary BOLT contains 4.6, 5.6, 8.8, 10.9, 12.9, etc.; It can be seen that the material strength is not the key to distinguish between high strength bolts and ordinary bolts.