The standard specifies hexagon head bolts with thread specifications of M3~M64, grades A and B. Grade A is used for bolts with D<=24 and L<=10D or L<=150mm (whichever is smaller); grade B is used for bolts D > 24 or L > 10 D or L > 150 (according to the smaller value) bolt size specification mark: thread specification D = M12, nominal length L = 80mm, performance level is 8.8, the table is the same as oxidation, A level Hexagon head bolt tag example bolt GB / T5782-86-M12 × 80 national standard common hex bolt head on the side size and cooperation national standard wrench thread diameter \ pair of edge sidewalls Skin wrench Wrench Double-ended open-end wrench Double-ended Torx wrench. The outer hexagon bolt is the most frequently used type of bolts. The main function of the external thread it has is to cooperate with the nut. Using this threaded connection method, the two parts are integrated. Grade C hexagon bolts are mainly used in steel structure machinery and equipment with relatively rough surface and low precision requirements. Grade A and Grade B hexagon bolts are mainly used in machinery and equipment with smooth surface and high precision requirements. Most of the stainless steel outer hexagon screws are full-tooth and hexagonal head full-tooth bolts. Standard: DIN933, GB5783, ISO4017, ANSIB18. 2.1, JISB1180; non-full thread bolt standards DIN931, GB5782, ISO4014, ANSIB18.2.1, JISB1180.
In some embodiments, the rivet fixing mechanism includes a left moving block, a right moving block, a return spring and a bracket, wherein both the left moving block and the right moving block are movably mounted on the bracket, and the left moving block and the right moving block are connected by a return spring, The insertion mouth can extend between the left moving block and the right moving block, and withstand the left moving block and the right moving block. The left moving block is provided with a left half hole, and the right moving block is provided with a right half hole matching the left half hole. hole. Therefore, when the insertion nozzle is not inserted, the left moving block and the right moving block can be combined together by the return spring, so that the left half hole and the right half hole are combined into one hole to fix and position the rivet, and when the insertion nozzle is inserted When , the left moving block and the right moving block will be pushed up by the insertion mouth to separate the left half hole and the right half hole, so that the rivet is no longer fixed and can be inserted with the movement of the insertion mouth.
Further, the clamping mechanism includes two clamping plates placed between the two fixing blocks, a bearing seat is installed on one side of each of the clamping plates, a bearing is installed inside the bearing seat, and the bearing is The inner ring is snap-connected with an elastic adjustment screw, and the other end of the elastic adjustment screw penetrates the fixing block and is placed outside the fixing block.
The technical problem to be solved by Yueluo is to provide a medical self-locking screw, which can fix the inner screw inside the outer screw, expand the outer screw head through the thimble on the inner screw, and use the outer cone on the inner screw. The body expands, compresses the surrounding bone, and achieves a double locking effect through the self-locking between the internal and external screws; it can hook the surrounding fixed parts when the anti-retraction ring is retracted to achieve the anti-regression effect; effectively prevent false implantation. After a long period of service, the looseness, fretting and other adverse reactions of the body are used to solve the defects caused by the existing technology.
Commonly used screw materials in my country are No. 45 steel, 40Cr, ammoniated steel, 38CrMOAl, superalloy, etc. 1) No. 45 steel is cheap and has good processing performance, but poor wear resistance and corrosion resistance. Heat treatment: quenched and tempered HB220-270, high-frequency quenched HRC45--48. 2) The performance of 40Cr is better than that of No. 45 steel, but it is often plated with a layer of chromium to improve its corrosion resistance and wear resistance. However, the requirements for the chrome plating layer are relatively high. If the plating layer is too thin, it is easy to wear, and if it is too thick, it is easy to peel off. After peeling off, it will accelerate the corrosion, and it has been rarely used. Heat treatment: quenched and tempered HB220—270, hard chrome plated HRC>553) nitrided steel, 38CrMoAl have excellent comprehensive properties and are widely used. Generally, the nitride layer reaches 0.4-0.6 mm. However, this material has low resistance to hydrogen chloride corrosion and is relatively expensive. 4) The superalloy material is superior to other materials. This material does not need coating, and is mainly used for the raw halogen-free screw of injection molding machine. The material has high oxidation resistance and corrosion resistance.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: big ear hand-tightened ingot nuts, hexagon head screw screws, anti-loosening nuts, carbon steel square nuts and other products, we can provide you with suitable products Your fastener solution.