High-strength screw standard parts of the quality of what data
Mechanical properties: hardness, tensile strength, etc. are in line with the standard requirements Size: size is in line with the standard requirements. Thread: through the rules are in line with the requirements.
High strength bolts are made of high strength steel, or bolts that require greater preload. High-strength bolts are tightened with a special wrench nut, the bolt has a huge and controlled pre-tension, through the nut and the pad, the connector also produced the same size of the pre-pressure.
High strength bolts are used for connecting bridges, rails, high pressure and ultrahigh pressure equipment.
The other can be based on the corresponding use of the environment, to decide whether to accept or not accepted.
Material: Does the chemical composition meet the standard requirements Appearance: Good surface treatment: Does it meet the standard requirements? If 1 and 4 problems, this batch of bolts directly failed,
