Service HotlineThe material of the second combination screw: It is decided to use the test machine to test the material of the combination screw wire, which is divided into iron and stainless steel. Iron wire is divided into 1010 wire and 1018 wire, 10B21 wire, etc., stainless steel is divided into stainless steel 201, stainless steel 304, stainless steel 316 and so on. The provisions of the national label of three combination screws: Generally, those who have experience in combination screws can be separated by using the inner eye. The difference between hexagon heads. Use a caliper to measure out the three-combination screw specifications. How big is it, how long is it, how thick is the head of the combination screw, how thick is the flat washer, and what is the outer diameter of the flat washer. How many hours is the salt spray of the combination screw measured with a salt spray machine. Use the environmental test machine to test whether the three-combination screw is environmentally friendly. Still not environmentally friendly.
The classification of the second combination screw is divided according to the material of the screw wire and the hardness index of the screw wire. Generally, the two combination screws are divided into stainless steel and iron, and stainless steel is divided into stainless steel 201, stainless steel 304 and stainless steel 316. Iron is divided into three types: low carbon steel, medium carbon steel, and high carbon steel. Carbon steel combination screws refer to iron combination screws. Generally, iron combination screws are classified into grades 4.8, 8.8, 10.9, and 12.9. But in the market, the combination screws of grade 10.9 and grade 12.9 are rarely used, so we won't talk about it here. And the two combination screws on the market are more commonly used combination screws of grade 4.8 and 8.8. 4.8 grade combination screws are generally made of 1010A screw wire rods. After the screw wire rods are beaten into screws, they are combined with spring flat washers. After production, this 4.8 grade combination screw does not need to be hardened. Its hardness can reach 4.8. The 8.8 grade combination screw is generally made of 10B21 screw wire. After the screw wire is punched into a screw, it is equipped with a spring washer and a flat washer, and the three pieces can be combined and rubbed by an automatic spring-flat washer machine. Fasten the spring-flat washer combination on the screw, and the spring-flat washer will not fall off. After the combination screw is produced, it needs to be hardened to make the hardness reach 8.8. After the hardness reaches 8.8, we need to take it for electroplating. In order to prevent hydrogen embrittlement of the spring washer in the 8.8-level combination screw with added hardness, it is easy to break. In this way, it is necessary to carry out hydrogen removal treatment on the hardened combined screws, and the electroplating can only be done after the hydrogen removal.
The middle pins on upright and horizontal pianos are also called balance pins. The middle pins are installed on the middle sleepers of the keyboard frame and play the role of fixing the keys. Generally, there are 88 keys in the piano. The pins are matched with the pin holes, and the keys are installed on each middle pin one by one through the pin holes. Due to the large number of middle pins and keys, in the production and installation process, in order to ensure the flatness of the 88 keys after installation, it is necessary to debug the middle pins and keys one by one, or add paper circles to the middle fixed part on the middle pins. The flatness of the 88 keys is kept the same. This debugging method is extremely cumbersome and increases the workload of debugging. Moreover, when adding paper circles, the keys need to be disassembled frequently. Due to the limitation of the installation space of the keys, it is troublesome to disassemble the keys, and it is easy to install and disassemble the keys many times. Damage to the pin holes on the keys, degrading the quality of the piano.
The rubber ring and the metal ring are integrally bonded and vulcanized. It is a sealing ring used to seal the thread and flange connection. The ring includes a metal ring and a rubber gasket. The metal ring is rust-proof, and the rubber ring is generally made of oil-resistant nitrile rubber or fluororubber. Combination pads are available in metric and inch sizes, and the standard JB982-77 specifies the combination of metal pads and rubber. Combination sealing washer is used for threaded pipe joints and screw plug sealing. It is generally used with ferrule type pipe joints to block oil ports. It is mainly used for end face static sealing of threaded joints of hydraulic valve pipe joints. It is suitable for British and American standards. Inch thread and end face static seal at French and German standard metric thread connections, etc. The combined sealing gasket can be divided into A type and B type according to the structure; it can be divided into full package and half package according to the difference of rubber.
It is suitable for plates of various thicknesses, with a minimum thickness of 0.8mm. When using, the tail number Z corresponding to size A must be determined according to the thickness of the plate and the specification of the nut. The user selects samples and orders according to the tail number in the table according to the thickness of the plate; Accurate control, processing according to the tolerance size of 0-+0.075mm, is punching, and the nut should generally be installed from the broken surface of the plate. The installation process is generally achieved through press riveting operations, and must not be impacted and knocked in.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: corrugated gaskets, thick-bar half-thread bolts, 304 core-pulling iron natural color GB867 round head rivets, multi-drum stainless steel rivets and other products. We can provide you with the right fastener solution for you.
