Interpretation of how to look at the quality of the combination screw

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When we manufacture the combined screws and purchasers order the combination screws, we often say that the quality of the combination screws is just fine. So how do you see if the quality of the combination screw is good? The following is a brief introduction of the manufacturer of the combination screw manufacturer Zhu:
The quality of the combination screw should start with the screw wire of the combination screw manufacturer. The wire of the screw is the first level to determine the quality of the combined screw. The wire is not good. Even if the production equipment is advanced and the staff is skilled, it is impossible to produce high-quality combination screws.
In the second look, the quality of the combination screw product is seen from the overall aesthetics of the combination screw. A combination screw is formed, the size of the head of the screw, the superior appearance of the flat pad, the screw thread can not pass the stop gauge and so on. These are all things that need to be detected. A good combination of screws, the overall standard can meet the national standard requirements, or customer requirements.
Finally, the quality of the combination screw product is from the color of the plating. Of course, the combination screw of the iron needs to be plated, but the stainless steel combination screw is not needed. Most of them are passivated, in order to increase the salt spray of the stainless steel combination screw. The combination of the screw plating color, some do not control well, will produce a large color difference. This is not very good looking.
Matters needing attention when constructing high-strength bolts
1, quality matters needing attention
(1) Surface rust, oil stains, burrs on the bolt hole wall, and welding tumors should be cleaned up.
(2) After the contact friction surface treatment, the specified anti-scratch coefficient requirements shall be met. The high-strength bolts to be used shall be provided with matching nuts and washers.
(3) When the friction surface of the treated component is installed, it is not allowed to be contaminated with oil, dirt and other debris.
(4) The friction surface of the component should be kept dry during installation and should not be used in the rain.
(5) Strictly check and correct the deformation of the connected steel plate before installation.
(6) It is forbidden to hammer the bolt when installing to prevent the bolt thread from being damaged.
(7) The electric wrench that is regularly tested during use ensures the accuracy of the torque and operates in the correct tightening sequence.
2. Main safety technical measures
(1) The size of the wrench using the adjustable wrench should match the size of the nut. Do not use a small wrench to add a sleeve. Use a dead wrench for high-altitude work. If you use a spanner wrench, use a rope to secure it.
(2) When assembling the steel component connecting bolts, it is strictly forbidden to insert the connecting surface or the detecting screw hole by hand. When the horn plate is taken, the fingers should be placed on both sides of the horn plate.
Overview of locknut characteristics and application range
The nut is a part that tightly connects the mechanical equipment. It can be connected by the inner thread and the same size nut and screw. For example, the M4-0.7 nut can only be matched with the M4-0.7 screw (in the nut, the M4 refers to the nut). The inner diameter is about 4mm, 0.7 means the distance between the two threads is 0.7mm); the American products are also the same, for example, the 1/4-20 nut can only be matched with the 1/4-20 screw (1/4 finger nut) The inner diameter is approximately 0.25 inches and 20 fingers have 20 teeth per inch).
The DISC-LOCK locknut consists of two parts, each with a staggered cam. Since the internal wedge design has a slope angle greater than the nut angle of the bolt, this combination is tightly bitten into a whole, when vibration occurs. At the same time, the convex portions of the DISC-LOCK locknut are mutually displaced, and the lifting tension is generated, thereby achieving a perfect anti-loosening effect.
Main features: easy to install; integrity; no need for gaskets; easy to disassemble; reusable; made of medium Carbon steel; can be used with 8.8, 10.9 and other high-strength bolts; through the US military MIL-STD 1312 Vibration; Test7.Results detection; detected by Junker Test; detected by Dynamic Test.
Applications: Automotive – cars, trucks, buses; compressors; construction machinery; wind power equipment; agricultural machinery; foundry; drilling equipment; shipbuilding; military; mining equipment; oil drilling rigs (onshore or offshore) ; public facilities; rail transit; transmission system; metallurgical equipment; rock hammer.
Rivet nut and its characteristics
The rivet nut is also called a rivet nut. The self-fastening nut is a kind of nut applied to a thin plate or a sheet metal. The shape is circular, and the embossing tooth and the guiding groove are provided at one end. The principle is that the embossing tooth is pressed into the preset hole of the sheet metal. Generally, the aperture of the pre-predetermined hole is slightly smaller than the embossing tooth of the rivet nut, and the pressure of the rivet nut is squeezed into the plate by pressure. The periphery of the hole is plastically deformed, and the deformed body is pushed into the guide groove, thereby producing a locking effect. The rivet nut is divided into fast-cut steel rivet nut S type, stainless steel rivet nut CLS type, stainless steel rivet nut SP type and copper and aluminum rivet nut CLA type, which should be used in different environment. . Specifications are usually from M2 to M12. There is no uniform national standard for rivet nuts, which are often used in chassis cabinets and sheet metal.
The difference between the use of screws and bolts
Screws and bolts are used differently. Screws are generally used to connect fixed parts, and most of them are used for fastening and easy to install and disassemble. The strength of the screw does not have the strength of the bolt. Bolts are stronger than screws, so they are often used as a force-bearing part, that is, in addition to the general fastening effect, bolts can usually withstand large forces. A reasonable design should allow the bolt to withstand tension or pressure without being subjected to shear forces. In most cases, the screws are often used to screw into the threaded holes of the part and are rarely used for coupling nuts. The bolts are used in the opposite direction, generally tightened with the nut and less tightly threaded between the threaded holes of the part. Of course, this is not absolute. Unconventional situations are not necessarily unreasonable, but they must be used flexibly.

SIC

Emery, also known as Silicon Carbide (SiC), is produced by high-temperature smelting of resistance furnaces using quartz sand, petroleum coke (or coal coke), and sawdust (need to add salt when green silicon carbide is produced). Silicon carbide also has a rare mineral, Moissanite, in nature. Silicon carbide is also called carbon silica. Among the non-oxide high-tech refractory raw materials such as C, N, B, etc., silicon carbide is the most widely used and the most economical one, and it can be called gold grit or refractory sand. At present, China's industrial production of silicon carbide is divided into two types of Black Silicon Carbide and green silicon carbide, are hexagonal crystals, the specific gravity of 3.20 ~ 3.25, the microhardness of 2840 ~ 3320kg/mm2.

Silicon carbide has two common basic varieties of black silicon carbide and green silicon carbide, both of which are α-SiC. 1 Black silicon carbide contains about 95% of SiC. Its toughness is higher than that of green silicon carbide. It is mostly used for processing low tensile strength materials such as glass, ceramics, stone, refractory materials, cast iron and non-ferrous metals. 2 Green silicon carbide contains more than 97% SiC, self-sharpening, mostly used for processing hard alloys, titanium alloys and optical glass, also used for honing cylinder liners and grinding high-speed steel cutters. In addition, there is cubic silicon carbide, which is a yellow-green crystal made by a special process, used for the production of abrasives for bearing superfinishing, surface roughness can be processed from Ra32 ~ 0.16 microns to Ra0.04 ~ 0.02 micron.

 

Silicon Carbide

Silicon Carbide,Black Silicon Carbide,Silicon Carbide For Abrasives,High Purity Silicon Carbide

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