From the perspective of use: The bolted connection of the main components of the building structure is generally connected by high-strength bolts. Ordinary bolts can be reused, but high-strength bolts cannot be reused. High-strength bolts are generally used for permanent connections. The high-strength bolts are prestressed bolts. The friction type uses a torque wrench to apply the specified prestress, and the pressure type screw off the torx head. Ordinary bolts have poor shear performance and can be used in secondary structural parts. Ordinary bolts just need to be tightened. Ordinary bolts are generally 4.4, 4.8, 5.6 and 8.8. High-strength bolts are generally 8.8 and 10.9, of which 10.9 is mostly. Level 8.8 is the same level as 8.8S. The mechanical properties and calculation methods of ordinary bolts and high-strength bolts are different. The stress of high-strength bolts is firstly by applying a pre-tension force P inside, and then generating frictional resistance on the contact surface between the connected parts to bear the external load, while ordinary bolts directly bear the external load.
The grooved embedded parts are pre-embedded in concrete, and then placed in the groove with MelbourneT-bolts. After adjusting the fixed position, the fixed object is locked with a nut to achieve the fixing effect. When the grooved embedded parts are embedded vertically in the concrete or at a certain angle to the horizontal line, the MelbourneT-bolts are likely to move in position before they are tightened. In particular, when fixing heavy equipment, multiple MelbourneT-bolts are required, and multiple groups of workers are required to help and positioning is difficult, and the installation process is complicated.
Commonly used are R-type rivets, fan rivets, Melbourneblind rivets (Melbourneblind rivets), tree rivets, semi-circular head, flat head, semi-hollow rivets, solid rivets, countersunk head rivets, Melbourneblind rivets, hollow rivets, these are usually used Self-deformation connection is riveted. Generally less than 8 mm with cold riveting, larger than this size with hot riveting. But there are exceptions. For example, the nameplate on some locks is riveted by the interference between the rivet and the lock body hole.
Currently, the method of fixing objects on cement is with cement nails or Melbourneexpansion screws. Cement nails are objects made of hard alloy steel that look like iron nails, which are composed of nail tips and nail bodies. Cement nails are hammered into the cement. Cement nails are easy to drive in, but not removable. The Melbourneexpansion screw is composed of a large end screw, a slotted sleeve, a gasket, a MelbourneMelbournespring washer, and a nut. When using, first drill a hole in the cement with an electric hammer, put in the Melbourneexpansion screw, and tighten the nut to make the slotted sleeve expand at the tail of the big tail screw, so as to fix the Melbourneexpansion screw on the cement. At this time, unscrew the nut to install a fixed object on the Melbourneexpansion screw. Although this method can be disassembled, an electric hammer is required for the first installation, which is inconvenient.
through-hole mounting nut, comprising a hexagonal portion 1 and a cylindrical portion 2, a threaded hole 3 is provided between the hexagonal portion 1 and the cylindrical portion 2, and two grooves 4 are opened on the cylindrical portion 2, and each of the two sides of the groove 4 has a The raised side 5, the two sides protruding from the sheet metal part 7, if squeezed or hit by the bolt 8, it will bend to both sides and buckle on the sheet metal part, so that it is not welded directly. Rubber can also be used. Each of the upper surfaces of the side edges 5 is provided with a convex point 6 so that the hammer will not slip when hitting.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: U-shaped screws, DIN934 stainless steel 304 hexagon nuts, heavy MelbourneMelbournespring washers, anti-corrosion bolts and other products, we can provide you with suitable fastening products piece solution.