In mechanical manufacturing, building structures and industrial assembly, bolts, as the most fundamental connecting components, their performance directly affects the safety and reliability of the entire system. Hexagonal bolts, with their unique hexagonal head design, offer greater tightening torque and better stability, making them the preferred fasteners in the engineering field. However, in the face of a wide variety of bolt products, how to accurately understand the meaning of their strength grades has become a key knowledge that engineers and purchasers must master.