Classification of Hot Dip Galvanized Hexagon Bolts

Hot dip galvanized hexagon bolts are divided into ordinary and reamed ones. According to the head shape: there are hexagonal head, round head, square head, sink head and so on. The hexagon is the most commonly used. The countersunk head of hot-dip galvanized bolt is generally used in the place where connection is required.
The non-standard parts are U-shaped, so they are called U-shaped bolts. The two ends of hot-dip galvanized bolts are threaded and can be combined with nuts. They are mainly used to fix tubular objects such as water pipes or sheet-like leaf springs of automobiles. Because the way of fixing objects is the same as that of people riding on horses, they are also called riding bolts.
For the connecting bolts used in steel structure, the hot-dip galvanized bolts are generally ordinary coarse grade C bolts. ① The bolt rods of Grade A and B bolts are processed by lathe, with smooth surface and accurate size. The material performance grade of hot-dip galvanized hexagon bolt is grade 8.8, which is complex in manufacture and installation, high in price and rarely used; Grade C bolt is made of rough round steel, and its size is not accurate enough. Its material performance grade is 4.6 or 4.8. Shear connection has large deformation, but it is easy to install and has low production cost.

Magnetic particle inspection of hot dip galvanized hexagon bolts is to use the interaction between magnetic leakage field and magnetic powder at bolt defects. Aiming at the difference of permeability of defects (such as cracks, slag inclusion, mixture, etc.) of bolts and the permeability of steel, the magnetic field at the discontinuities of these materials will change after magnetization, forming a part The magnetic leakage field is produced on the surface of the workpiece where the magnetic flux leakage occurs, so as to attract the magnetic powder to form the magnetic particle accumulation at the defect position. The hot-dip galvanized bolt shows the position and shape of the defect under the appropriate lighting conditions. The purpose of eliminating the defective products is to observe and explain the accumulation of these magnetic particles.