Wholesale quenched and hardened flat tail self-tapping screw cross recessed round head screw pan head self-tapping screw self-tapping 5/8

In the existing life, repair parts are often used to repair the cassettes with damaged screw holes, and the screw holes on the repair parts are used instead of the original damaged cassette screw holes. However, in the prior art (application number: 201520948368.1), the restoration is fixed by rotating the support of the restoration, which is often inconvenient due to the small space of the cassette. In addition, the set screw in the prior art mainly fastens the object through the end of the screw without threaded holes, which makes it difficult to install external screws. Based on this, a method of extruding the support through a set screw with screw installation holes and tightening the repair piece, and then installing the screw on the set screw, will facilitate the quick installation and use of the repair piece.

(1) The screw-in performance test is to screw the self-tapping locking screw sample into the test plate until one complete thread completely passes the test without breaking. (2) The destructive torque test is to clamp the stem of the self-tapping locking screw specimen in a thread mold or other device that matches the screw thread, and uses a calibrated torque-measuring device to measure the screw. Torque is applied until fracture, which should not occur in the clamped threaded portion. (3) Carry out a tensile test on the screw sample to check the minimum tensile load for failure. The fracture should be within the length of the rod or the unthreaded thread, and should not occur at the junction of the nail head and the rod. Before the sample breaks, it should be It can reach the minimum tensile load specified by the corresponding performance class. (4) Hydrogen embrittlement is a problem that must be strictly paid attention to in the surface treatment process of self-tapping locking screws. In the pickling process, the screw is stirred in dilute hydrochloric acid, and the amount of hydrogen absorbed by the pickling steel increases linearly with the square root of time and reaches the saturation value. Less than 100%, a large number of hydrogen atoms will be produced, which will be attached to the surface of the screw, resulting in hydrogen infiltration, and the steel will become brittle due to the absorption of hydrogen. The self-tapping locking screw takes 6~8h to drive hydrogen, and the temperature is 160~200℃ (phosphating) and 200~240℃ (electroplating). However, in the production process, the hydrogen drive time should be determined according to many production conditions such as core hardness, surface roughness, electroplating time, coating thickness, pickling time, and acid concentration. It is best to do it before passivation and just after electroplating.

new type of screw includes a fixing object and a screw body composed of a nut, a fixing piece and a screw rod. An outer gear ring is fixedly sleeved on the fixing piece, and a support plate is arranged on the lower side of the outer gear ring. The upper side of the support plate is connected with a mounting frame through an adjustment mechanism, the inside of the mounting frame is connected with the outer gear ring through an anti-drop mechanism, and a mounting plate is fixedly connected to the side of the support plate close to the fixed object, and the mounting plate is clamped The coupling mechanism is connected to the fixture.

The technical problem to be solved by Guangdong Yueluo Hardware Industry Co., Ltd. is to overcome the deficiencies of the existing rivets. The purpose of this utility model is to provide a special rivet for railway freight cars, which can be reused and increase the safety factor. , to limit the movement of the collar in the circumferential direction.

The above content is uploaded by Yueluo or the Internet. If there is any copyright issue, please contact [email protected].