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Countersunk head fine tooth bolt flat head screw lengthened cylindrical step screw long rod screw long screw

author:[email protected] Click:3344end source: time:2023-04-18 16:36:22

Summary of information:We have more than ten years of production experience in the screw industry, the main products are: hexagon socket length...

There are many types of T-bolts used with pre-embedded chutes, which are used for the connection of external components of pre-embedded chutes embedded in segments, U-beams, building concrete, etc. The fixing of the chute on the forming die. When producing segments and U-shaped beams, the embedded chute is fixed on the forming mold by T-bolts. During the concrete pouring process, the tightening nut is easily covered by concrete. In this way, the concrete on the fastening nut should be removed, but it is difficult to remove the concrete, which will cause inconvenience to the disassembly of the forming mold after the production of the segment and the U-shaped beam.

The spring self-locking nut is a spring clip self-locking nut, which consists of an S-shaped spring clip and a self-locking nut. The S-shaped spring clip is provided with a fixing hole (3) for fixing the self-locking nut, which is used for the transition through the bolt. The self-locking nut is placed between the clamping hole and the transition hole (4), and is clamped in the clamping hole. The utility model adopts the elastic force of the spring clip to fix the self-locking nut on the connecting plate or the support. Not only is it convenient to install, but also has good reliability after installation.

Stainless steel screws are classified into austenitic stainless steel, ferritic stainless steel, martensitic stainless steel, and precipitation hardening stainless steel. The selection of stainless steel screws is also based on principles. Where to start, let you choose the stainless steel screws you need. After comprehensive and comprehensive consideration of these five aspects, the grades, varieties, specifications and material standards of stainless steel screws are finally determined. Austenitic stainless steel: the most basic alloying elements of austenitic stainless steel are chromium and nickel. The grade is a chromium-nickel austenitic stainless steel with a chromium content of about 18% and a nickel content of about 8%, often called 18-8 stainless steel. The element ratio of chromium and nickel basically ensures that the structure of the steel is stable austenitic ferritic stainless steel: 430 type ordinary chromium steel, its corrosion resistance and heat resistance are better than 410 type, magnetic, but it It cannot be strengthened by heat treatment, and is suitable for stainless steel screws with slightly higher corrosion resistance and heat resistance and general strength requirements. Martensitic stainless steel: Type 410 and 416 can be strengthened by heat treatment, with a hardness of 35 to 45HRC, and good machinability. They are used for general-purpose heat-resistant and corrosion-resistant stainless steel screws. Type 416 has a slightly higher sulfur content and is a free-cutting stainless steel. Type 420, sulfur content? R0.15%, improved mechanical properties, can be strengthened by heat treatment, maximum hardness value of 53 ~ 58HRC, used for stainless steel screws requiring higher strength. Precipitation hardening stainless steel: 17-4PH, PH15-7Mo, they can get higher strength than the usual 18-8 type stainless steel, so they are used for high-strength, corrosion-resistant stainless steel stainless steel screws. A-286, a non-standard stainless steel, has higher corrosion resistance than commonly used Type 18-8 stainless steels, as well as good mechanical properties at elevated temperatures. Used as high-strength, heat-resistant, corrosion-resistant stainless steel screws, can be used to 650 ~ 700 ℃. Austenitic stainless steel: The commonly used models are 302, 303, 304, and 305, which are the so-called 18-8 austenitic stainless steels. Both corrosion resistance and mechanical properties are similar. The starting point of selection is the production process method of stainless steel screws, and the method depends on the size and shape of stainless steel screws, and also depends on the quantity of production. Type 302 is used for machined screws and self-tapping bolts. Type 303 In order to improve machinability, Type 303 stainless steel is added with a small amount of sulfur and is used to machine nuts from bar stock. Type 304 is suitable for hot heading stainless steel screws, such as longer gauge bolts, large diameter bolts, which may be beyond the scope of the cold heading process. Type 305 is suitable for cold heading processing of stainless steel screws, such as cold formed nuts, hex bolts. Type 309 and Type 310, their Cr content and Ni content are higher than 18-8 type stainless steel, suitable for stainless steel screws working at high temperature. Types 316 and 317, both of which contain the alloying element Mo, have higher high temperature strength and corrosion resistance than 18-8 type stainless steel. Type 321 and Type 347, Type 321 contains a relatively stable alloying element Ti, Type 347 contains Nb, which improves the intergranular corrosion resistance of the material. It is suitable for stainless steel standard parts that are not annealed after welding or serve at 420~1013℃.

At present, the industry uses the pure manual installation method to install the elastic cylindrical pin, that is, the staff first holds the tool holder; then, manually puts the elastic cylindrical pin into the elastic cylindrical pin hole of the tool holder; then, use the body to align the tool holder For positioning, use a hammer to knock the elastic cylindrical pin into the tool holder. This installation method requires manual operation throughout the entire process, and the work efficiency is low. Moreover, when the hammer is knocked, the staff needs to use the body to position the tool holder, there is a risk of smashing and injuring people, and there is a potential safety hazard. In addition, hammering will cause deformation of the elastic cylindrical pin, and the qualification rate of assembly is low.

The fixing screw proposed by Guangdong Yueluo Hardware Industry Co., Ltd. has a screw body 1, and the axial surface of the screw body 1 is formed with extending screw teeth 6, and the axial surface is a column along the central axis direction of the cylinder of the screw body 1. The body surface has a hemispherical screw tail 7 at the bottom, and a screw head 2 at the top. The upper surface of the screw head 2 is provided with a slot (not shown). The screw body 1 is composed of the upper tapered rod 4 and the lower cylindrical screw 5. The tapered rod 4 is an inverted cone, the diameter of its circular upper surface and the diameter of the screw mounting hole 10. equal. The fixing screw also has a washer 3, the washer 3 is arranged between the screw head 2 and the screw body 1, the lower surface of the cylindrical washer 3 has a number of teeth 8, the teeth 8 are along the The upper surface of the inverted cone of the tapered rod 4 and the edge of the washer 3 are connected to form a straight convex strip 15 extending outward; the convex strip 15 can also be designed in an arc shape. The fixing screws for installation proposed by Guangdong Yueluo Hardware Industry Co., Ltd. can be made of metal materials in one piece. As shown in Figure 3, it is a schematic diagram of the installation of Guangdong Yueluo Hardware Industry Co., Ltd. for PCB board fixing. When installing, first pass the screw body 1 of the fixing screw through the mounting hole 10 and the copper column 11 provided on the PCB board 9, so that the tail 7 of the screw reaches the mounting hole 13 on the casing 12, and then use the tightening tool 14 to insert the screw At the notch on the top of the head, forcefully press the inverted cone design taper rod 4 of the screw body 1 into the mounting hole 10, so that the tail 7 passes through the mounting hole 13. Due to the outer diameter D at the bottom of the taper rod and the screw mounting hole The aperture size of 10 is equal, and the fixing screws are pressed and fixed, so that the PCB board 9 can be automatically corrected in the process of fixing its front, back, left and right deflections, and the accuracy of the installation position of the PCB board 9 can be ensured. As shown in Figure 4, after the fixing screw is screwed into the casing, the washer 3 is fully contacted and pressed on the PCB board 9, and the PCB board 9, the copper column 11 and the casing 12 are firmly connected together without sliding. . The teeth 8 on the washer 3 are in full contact with the surface of the PCB board 9, so that a ground wire path is set up between the PCB board 9 and the casing 13 by the metal fixing screw 1, thereby ensuring that the PCB board 9 is fully grounded , the design of the teeth 14 on the washer 3 also has a non-slip function. The fixing screws for installation designed by Guangdong Yueluo Hardware Industry Co., Ltd. make use of the cooperation, friction and electrical conductivity in the mechanical connection, which fully guarantees the firm installation of the PCB board and the chassis and the good grounding of the PCB board. Moreover, the ellipsoid tail of the fixing screw The surface is relatively smooth, even if the mounting holes are exposed, it will not cause scratches on the hands and desktop. The above is only the embodiment of Guangdong Yueluo Hardware Industry Co., Ltd., and does not limit the scope of Guangdong Yueluo Hardware Industry Co., Ltd., any equivalent structure made by using the contents of the description and drawings of Guangdong Yueluo Hardware Industry Co., Ltd. or etc. Effective process transformation, or direct or indirect application in other related technical fields, are also included in the protection scope of Guangdong Yueluo Hardware Industry Co., Ltd.

We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: black flat head bolts, order T-shaped nuts, stainless steel bolts, large lengthened screws and other products, we can provide you with fastener solutions suitable for you .

Countersunk Head Fine Thread Bolts

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