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Twist shear type high-strength bolts (troque shear style / Twist off bolts/) are usually abbreviated as TC, to distinguish them from the English abbreviation TCB (Tension control bolts). They have spline ends at their tips, and the bolt heads are generally round (mushroom-shaped) in this twist shear type: spline-head design. A torsional shear high-strength bolt consists of a high-strength bolt, a nut, and a washer to form a torsional shear high-strength bolt connection assembly. The specifications for torsion-shear high-strength bolts made of steel structures range from M16 to M30 (six thread sizes are available: M16, M20, M22, M24, M27, and M30). The length of these bolts varies from 40 mm to 220 mm. Their performance grades are 10.9 and 12.9S. The surface treatments available include phosphating, natural color, galvanizing, and blackening. Their performance parameters meet the requirements specified in the GB/T 3632-2008 standard for torsion-shear high-strength bolts. When installing torsional shear high-strength bolt connections, only one washer should be used on the nut side. The formula for calculating the initial tightening torque is: Tc=0.065*Pc*d. Here, Tc represents the initial tightening torque, in N·m ； Pc is the pre-tensioning force during construction, in kN ； d is the thread diameter of the high-strength bolt, in mm. The final tightening is done by using a wrench to break the hex head at the tail. The focus of quality inspection should be on the supervision and inspection during the construction process. Torsion-shear high-strength bolts are an improved version of large hexagonal high-strength bolts, designed for better construction. A large hexagonal high-strength bolt consists of a bolt, a nut, and two washers. A torsional shear type high-strength bolt consists of a bolt, a nut, and a washer. Product model: GB/T3632~3633-2008 national standard. Product specifications: Size range: M16 ~ M30. Material: 20MnTiB and 35VB alloy steels. Surface treatment: Blackening, hot-dip galvanizing, Dacromet coating. Features of high-strength torsional shear bolts for steel structures: 1. The bolt is formed through cold forging in the same factory, with the head, tail end, threads, and grooves all being manufactured there; this results in excellent processing precision and consistent quality. 2. Continuous strip heat treatment furnaces are used for heat treatment. Its standard temperature and carbon concentration are automatically recorded, enabling effective control of the quenching temperature and gas concentration to prevent carburization or decarburization and ensure that the bolts achieve the required mechanical properties. 3. Make effective use of control charts and process capability analysis methods to thoroughly implement process control, track processing and quality conditions, and provide comprehensive data for reference by engineering designers. 4. Given the special characteristics of torsion shear bolts, and to prevent them from sliding or rotating during installation, we added anti-slip measures below the heads of these bolts during the design and manufacturing process. This effectively avoids safety and quality issues that can arise from improper installation due to bolt slippage.