Classification
Friction-type high-strength bolts: suitable for connections between beams and columns of steel frame structures, solid web beam connections, heavy-duty crane beam connections in industrial plants, braking systems and important structures that bear dynamic loads.
Pressure-bearing high-strength bolts: can be used for shear connections in statically loaded structures that allow a small amount of sliding or in components that indirectly bear dynamic loads.
Tensile-type high-strength bolts: When the bolt is under tension, its fatigue strength is low. Under dynamic load, its load-bearing capacity cannot easily exceed 0.6P (P is the allowable axial force of the bolt). Therefore, it is only suitable for use under static load. Such as flange butt joints of pressure rods, T-shaped joints, etc.
Precautions
Quality considerations
Surface rust, oil stains, burrs on the bolt hole wall, welding flash, etc. should be cleaned up.
The contact friction surface must meet the specified anti-scratch coefficient requirements after treatment. The high-strength bolts used should have matching nuts and washers. They should be used as matching sets and must not be interchanged.
The friction surface of the treated components is not allowed to be stained with oil, dirt and other debris during installation.
During installation, the friction surface of the component should be kept dry and should not be operated in the rain.
Strictly check and correct the deformation of the connected steel plates before installation.
It is prohibited to hammer into the bolts during installation to prevent damage to the bolt threads.
The electric wrench should be tested regularly during use to ensure the accuracy of the torque and operate in the correct tightening sequence.
