Service HotlineThe anti-theft screw of this structure has two disadvantages. One is that the polygonal block moves up and down in the polygonal hole, and the polygonal hole in the connecting piece and the polygonal hole on the threaded part have no limit structure. Because of the polygonal structure, the two If the polygonal holes of the parts cannot be aligned, dislocation occurs, and any edge may block the up and down movement of the polygonal block, which is very unsmooth during use. The second is that the shell of the lock cylinder and the hexagonal part are connected by pins, and the pins are exposed on the hexagonal parts, which are easily damaged and leave opportunities for theft; once the pin is pried off, the lock cylinder will be taken out, and the entire anti-theft screw will be lost. and the pin fixation is sometimes unstable, which is detrimental to theft.
Standard screw is one of the fasteners commonly used for fastening and assembly. Standard screws and flat washers, grade A, and standard spring washers, are used in combination, and are widely used in the assembly of various products. For manufacturers who use combination screws in small and medium batches, the process of combining screws, spring washers and flat washers generally adopts the method of assembling screws by workers' bare hands. This method is tedious and repetitive, wastes human resources, is time-consuming and labor-intensive, and it is difficult to ensure the normal operation of the workshop. assembly progress. The screw assembly machines currently on the market can replace manual assembly screws, but this type of equipment has disadvantages such as bulky size, high cost, complex structure, inconvenient non-standard manufacturing and maintenance, high noise, and power consumption.
Yueluo relates to a self-tapping screw according to the preamble of claim 1. A self-tapping screw is known from EP0623759B1, the ratio of the outer diameter to the smaller diameter of the self-tapping screw is about 1.25-1.5, the ratio of the outer diameter to the pitch lead is about 1.5-1.6 and the thread The flank angles of , are < 50° and ≥ 35°. EP0433484B1 proposes a self-tapping screw whose thread is provided with cutting teeth of approximately arcuate design, and the cutting edge and the thread crest are at the same horizontal position and are set in opposite directions. One purpose of Yueluo is to realize a general type of self-tapping screw so that it can be screwed particularly easily into holes drilled in concrete or other materials such as bricks and the like. According to Yueluo, this object is achieved by the features in the characterizing part of claim 1, and surprisingly, it has been found that the parallel arrangement of the flanks, ie with a flank angle of about 0°, will make screwing particularly easy when screwing in , especially if the diameter of the hole varies within an allowable tolerance. One reason may be due to the fact that there is no lateral pressure on the material screwed into the thread, even if threads of different depths are cut in concrete or other materials such as brick, chipped plywood, or hardwood. The thread cuts into the material over its entire width by cutting grooves. In particular according to the embodiment of claim 13 the material cut out when screwing in the screw can be discharged without any accumulation, the dependent claims reflecting many advantages of further embodiments.
The purpose of Guangdong Yueluo Hardware Industry Co., Ltd. is to provide a cement screw that is easy to install and can be removed in view of the shortcomings of the above-mentioned cement nails that cannot be disassembled and the expansion screws are not easy to install for the first time. Guangdong Yueluo Hardware Industry Co., Ltd. is a cement screw, which is realized by the following technical solutions. The cement screw is composed of a nail tip and a nail body. There is a thread at the back of the nail body. This thread can be an internal thread or an external thread. . When using, use a hammer to drive cement screws into the cement, and you can use ordinary screws or nuts to freely screw in and out to install and fix objects. Compared with the existing technology, Guangdong Yueluo Hardware Industry Co., Ltd. has the advantage that there are internal threads or external threads on the back of the cement screw, so it is not only easy to install for the first time, but also the objects to be installed can be disassembled repeatedly. Used as a fastener when installing objects on cement that may need to be dismantled.
Please refer to FIG. 1 , which is a cross-sectional view of a conventional screw and screw washer for locking two metal parts. The screw 100 is combined with the screw washer 110 to lock the metal parts 120 and 130 . The screw washer 110 includes a washer portion 112 and a body washer portion 114 . The washer portion 112 is used for electrically isolating the screw head 102 from the metal piece 120 , and the screw body washer portion 114 is used for electrically isolating the screw body 104 and the metal piece 120 . Therefore, through the design of the screw washer 110 , the screw 100 can be isolated from conducting the metal parts 120 and 130 .
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: flat head screws, DIN970 hexagon nuts, black zinc pan head screws, external hexagon cross recessed bolts and other products, we can provide you with suitable screws for you. Firmware Solutions.
