Bolts are one of the most basic and widely used mechanical fasteners, typically used in conjunction with nuts to connect and fasten two or more components with through holes. Their working principle involves the engagement of the external threads of the bolt with the internal threads of the nut, generating an axial clamping force through the application of torque, thereby securely fixing the connected components. The load-bearing capacity, anti-loosening performance, and application scenarios of bolts primarily depend on their head shape, thread specifications, performance grade, and manufacturing process, making them suitable for a wide range of demanding conditions, from light industry to heavy structures, high temperatures, and high pressures.