Service HotlineSubway tunnels can be divided into rectangular, arched, circular, and elliptical end face forms according to the section shape of the section tunnel. The rectangular end face can be divided into single-span, double-span and multi-span types. There are two types of circles. The subway tunnel needs to install electromechanical equipment through bolts, insert T-shaped bolts into the preset holes on the shield plate of the subway tunnel, and then cast and fix it. The bolts are smooth and the contact surface is small. The bolts installed in the shield plate are easy to fall off, causing the installed equipment to fall and damage or causing losses to pedestrians or vehicles passing in the tunnel. Therefore, it is necessary to further improve the current bolts.
Bolt: A mechanical part, a cylindrical threaded fastener with a nut. A type of fastener consisting of a head and a screw (a cylinder with an external thread), which needs to be matched with a nut to fasten and connect two parts with through holes. This form of connection is called a bolted connection. If the nut is unscrewed from the bolt, the two parts can be separated, so the bolt connection is a detachable connection.
1) Scope This standard specifies the lock nut (referred to as nut), the size of the locking device, technical requirements, acceptance rules and measurement methods. This standard applies to the design, production, inspection and user acceptance of nuts and locking devices for tapered bushings. 2) Terminology The terms used in this standard conform to the provisions of GB/T 6930. This standard specifies the marking system, index, test method and marking of the mechanical and working performance of the effective torque section steel hexagonal lock nut. This standard is applicable to coarse thread 6H class nuts made of carbon steel or alloy steel, the width across the sides conforming to the provisions of GB 3104, the nominal height is ≥ 0.8D, and the guaranteed load and effective torque need to be specified, and the thread diameter is 3 ~ 39mm. Except for the effective torque part, the thread size and tolerance are specified in GB 193, GB 196 and GB 197. The working temperature range of the nut should be in accordance with: All-metal nut without electroplating treatment: -50℃～+300℃. All-metal nuts with electroplating treatment: -50℃～+230℃; nuts embedded with non-metallic elements: -50℃～+120℃. This standard does not apply to nuts with special performance requirements (such as weldability and corrosion resistance). For stainless steel and non-ferrous metals with fine pitch lock nuts or thin nuts made of carbon steel or alloy steel, the performance indicators and test methods of effective torque specified in this standard may be adopted by mutual agreement.
Traditionally used for plastic fastening screws, most of the thread designs are self-tapping threads, but for different plastic types, the self-tapping threads also have many different classifications, such as PT profile, Plastite series, Remform profile, etc. The structural parameters and manufacturing process of these threads are inconsistent, or require different main molds and wires. Therefore, to find a plastic screw that is universally applicable to various plastic types, has a single pressing structure, low-cost and simple manufacturing process, especially its special self-tapping thread, is an important issue that needs to be solved urgently at present. question. The purpose of Yueluo Yueluo Guangdong Yueluo Hardware Industry Co., Ltd. is to propose a plastic screw to solve the screw fastening problem that is generally applicable to different plastics. The purpose of Yueluo Guangdong Yueluo Hardware Industry Co., Ltd. is to realize a kind of plastic screw through the following technical scheme, it is characterized in that, the thread of the screw is composed of asymmetric threads with a profile angle of 30°, and the threads are The bottom surface of the connection between them is an arc surface. Yueluo preferably, the asymmetrical thread has a forward thread angle greater than the reverse thread angle, and the sum of the two-direction thread angles is 30°. Yueluo further preferred that the tooth profile angle of the asymmetrical screw thread in the forward mounting direction is 20 degrees, and the tooth profile angle in the reverse mounting direction is 14 degrees. Yueluo Guangdong Yueluo Hardware Industry Co., Ltd.'s application of plastic screws, through the improvement of special thread structure, reduces the radial pressure and installation torque when the screw is installed, reduces the damage to the plastic hole; and increases the pull-out resistance of the screw force, it is not easy to appear loose assembly. At the same time, the design of the bottom surface of the connection between the threads of the arc optimizes the flow of the material of the installation object, which improves the integrity of the installation connection.
Cylindrical pins are widely used, and they are usually provided with matching pin holes. For the tails of cylindrical pins exposed outside the pin holes, they usually do not have a guiding function, which cannot meet the needs of quick installation of workpieces.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: light round head rivets, round cup screws, natural hexagon nuts, stopper bolts and other products, we can provide you with suitable fastening products piece solution.
