Both are nuts, and there is still a significant difference between high-strength nuts and ordinary nuts< Br> Ordinary hexagonal nuts have three drawbacks in bolt support technology:
(1) When an ordinary nut is equipped with a Grade II steel rod body, the maximum failure stress of the inner thread of the nut is less than 70% of the rod body. Due to the first failure of the internal thread of the nut, the waste of rod material and the increase of unsafe factors have been caused
(2) If ordinary nuts are used, an additional step of dismantling the nuts will be added when installing the bolts, resulting in longer working hours and lower work efficiency
(3) When ordinary nuts are subjected to underground vibration and vibration, sometimes the steel wire may shrink, leading to a decrease in bolt anchoring force and accelerating roof deformation
Characteristics of high-strength nuts:
(1) Easy to install; Integrity; No washing machine required; Easy to disassemble; Reusable medium carbon steel is used for manufacturing materials. The connection structure is simple, with good mechanical performance, disassembly, fatigue resistance, and no looseness during dynamic load. This is a very promising connection method
(2) High strength nuts are used to tighten special wrench nuts, causing the bolt to generate a huge and controlled pre tension through the nut and buffer plate, applying the same size of pre pressure on the joint. Under the action of preload, there will be greater friction along the surface of the connector. Obviously, as long as the axial force is less than the frictional force, the part will not slide and the connection will not be damaged. This is the principle of high-strength nut connection<
High strength nuts are steel used for fasteners and have high interchangeability produced through the cold heading process. Due to its formation through metal plastic processing at room temperature, each component undergoes large deformation and high deformation rate. Therefore, the performance requirements for high-strength nut raw materials are very strict.