Service HotlineThe core rivet is another type of single-sided riveting. When riveting, the head of the rivet is hit with a hammer to expose the core, so that it is flush with the end face of the nail head, that is, the riveting operation is completed, which is very convenient, especially suitable for inconvenient Riveting occasions using ordinary rivets (which must be riveted from both sides) or blind rivets (lack of a rivet gun). Usually use flat head rivets, countersunk head rivets are suitable for occasions where smooth riveting is required on the surface.
GB bolts are generally divided into two types: GB30 bolts and GB21 bolts. The difference is that the hexagonal head of GB30 is larger than that of GB21. The materials are all used: Q235. The grade is 4.8, the hardness is weak, and it is used for parts with low hardness requirements and infrequent activities, which are called ordinary bolts. The most typical use: machinery, construction, fixing, fastening.
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 11 the result is that the material cut out when screwing in the screw can be discharged without any accumulation, the dependent claims reflecting many advantages of further embodiments.
In a traditional spring mattress, there are two layers of spring pads that are independent of each other. The manufacturing process of this kind of mattress is complicated, time-consuming and material-consuming, and after long-term use, the springs in the two-layer independent spring cushion are prone to translocation, which deforms the mattress and affects people's sleep.
Regardless of stainless steel plate or heat-resistant steel plate, austenitic steel plates have the best comprehensive properties, with sufficient strength, excellent plasticity and low hardness, which is one of the reasons why they are widely used. Austenitic stainless steel is similar to most other metal materials, its tensile strength, yield strength and hardness increase with the decrease of temperature; plasticity decreases with the decrease of temperature. Its tensile strength increases uniformly in the temperature range of 15~80°C. More importantly: as the temperature decreases, the impact toughness of stainless steel screws decreases slowly, and there is no brittle transition temperature. Therefore, stainless steel can maintain sufficient plasticity and toughness at low temperature.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: percussion flat cap Liuding GB867 stainless steel rivets, ingot-shaped stainless steel, cored expansion screws, GB29.2 screws and other products, we can help you Provide the right fastener solution for you.
