Service HotlineTherefore, in order to obtain fasteners that meet the requirements, it is usually necessary to anneal the middle sections of bolts, rivets, etc. to reduce the hardness of the middle sections, while ensuring the hardness of the heads of bolts, rivets, etc. At present, the existing process adopts ultra-high frequency induction heating equipment to instantly heat the middle section and reduce the hardness. However, this process requires a lot of control, and the heating time is slightly longer, which affects the hardness of the head, and the mass production is very unstable, which is easy to cause the rivet to fail. At the same time, the cost of ultra-high frequency equipment is high and the power consumption is large, which is not conducive to mass production and energy saving. Environmental friendly.
Countersunk head screw, also called countersunk head screw, also known as flat machine screw, is a kind of construction part. The head is a 90-degree cone, similar to common wood screws. The head has tool tightening grooves, such as a zigzag, cross, inner hexagon, plum blossom, pentagon, etc. Screws are all connectors used to connect two objects. Generally, the head of the screw will protrude above the surface of the object to be connected, so that the surface will lose its smoothness. Countersunk head screws can be sunk under the surface to make the surface flat. For hard objects, countersunk holes need to be drilled in the corresponding positions of the countersunk head. In short, the countersunk head is the head of the screw that can keep the surface flat after installation.
1. The expansion phenomenon of the spring washer is generally not the problem of the spring washer itself. 2. The spring washer with the expansion ring must be subjected to a radial external tension. The external tension is derived from the tightening axial force generated by the tightening torque. The chamfer creates a radial component of the axial clamping force, which expands the opening of the spring washer. The smaller the chamfer diameter, the greater the possibility of ring expansion. 4. Adding a flat washer between the nut and the spring washer helps to slow down or prevent the expansion of the ring, but the flat washer is too thin or too soft. Prevent ring expansion 5. The reason for the hydrogen embrittlement fracture of spring washers is generally due to unreasonable heat treatment process and the failure of hydrogen removal treatment after electro-galvanizing. A large number of tests and long-term practical experience have confirmed the above analysis.
It can be seen that the above processing method can only be used to process a relatively simple retaining ring (that is, only a ring body, which cannot be cut or punched), and the outer surface of the processed retaining ring still cannot be guaranteed to be completely flat.
There are generally two, one is iron, that is, carbon steel. One is stainless steel, and of course there are copper and aluminum nuts, but these are rarely used. Copper is more or less useful, and nuts like aluminum are rarely used.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: white zinc external screws, punched pins, knurled screws, flat head screws and other products, we can provide you with suitable fastener solutions for you Program.
