Service Hotline(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.
At present, the automatic nailing device on the domestic market lacks the restraint and arrangement of the rivets when they are out of the nailing device, which makes the rivets irregular and uncontrollable after the automatic nailing is completed, which has adverse effects on on-site use and maintenance, and is unstable. .
Material broadcast Cross recessed screws are made of iron and stainless steel. Iron cross recessed screws are also called carbon steel screws. Stainless steel cross recessed screws include stainless steel SUS201 and stainless steel SUS304, and stainless steel SUS316 cross recessed screws.
Alloy Steel Nuts Hexagon Nuts (GB6170/DIN934, GB6175), Flange Nuts (GB6177/DIN6923) Round Nuts (GB812), Small Round Nuts (GB810), American Square Nuts, American Hex Nuts (NI/MEB18.2.2), Heavy Duty Nuts (Metric, US). Specifications: 5/16-4. Nut Specifications Nut specification table is to unify all kinds of nuts in detail, and use the table to subdivide some specifications of nuts. There are many types of nuts, and there are nuts of different materials. Each type of nut has different specifications, and each type of screw also has its mechanical properties and functions.
The general nut will loosen itself due to vibration and other reasons during use. In order to prevent this phenomenon, the self-locking nut was invented. The main functions of self-locking nuts are anti-loose and anti-vibration. For special occasions. Its working principle is generally self-locking by friction. The types of self-locking nuts classified by function include those with nylon rings, those with neck closures, and those with metal anti-loosening devices. They are all effective torque type lock nuts (refer to GB/T3098.9-2002 national standard)
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: self-tapping self-drilling screws, round polyurethane gaskets, mushroom screws, circuit board copper posts and other products, we can provide you with suitable screws for you. Firmware Solutions.
