In the existing joint replacement, self-tapping screws are mostly used, and their triangular thread structure has a certain self-locking ability. After a long period of service, it is prone to loosening. The surrounding bone may not be tight enough after implantation, resulting in a sharp decline in its self-locking ability, and there may be a risk of regression, causing certain damage to the human body.
Self-tapping screw is a kind of threaded fastener that self-tapping and drilling the matching female thread in the pre-drilled hole of metal or non-metal material. When using self-tapping screw, a flat washer is often required to protect the fastening surface. Traditional When the self-tapping screw is used, the flat pad is easy to fall off, resulting in low work efficiency. In view of this, we propose a combined structure of the stuck self-tapping screw spring washer that prevents the flat pad from falling off.
Iron pans are traditional kitchen utensils for people to cook food. They generally do not contain toxic substances and will not oxidize. In the process of stir-frying and cooking food, there are very few dissolved substances in the iron pot. Even if there is iron dissolved out, it is also good for the human body. Cooking in the iron pot is the most direct way to supplement iron. The main types are India pot, ear pot, pan, oil pan, pancake pan. In the process of cooking dishes in an iron pan, a small amount of iron will dissolve in the food, supplement iron for people, supplement the iron-deficient part of the food itself, and play a role in preventing iron-deficiency anemia. Can increase the amount of iron in a person's diet. Therefore, as far as the prevention and treatment of iron deficiency anemia is concerned, cooking in an iron pan is beneficial to health.
In the prior art, the earliest rivets were small pegs made of wood or bone, and the earliest metal deformations were probably the ancestors of the rivets we know today. Without a doubt, they are the oldest known method of metal joining, dating back as far as the earliest use of malleable metals, for example: the Bronze Age Egyptians used rivets to attach six wooden sectors to the outer lines of a slotted wheel Riveted and fastened together. After the Greeks successfully cast large statues in bronze, they then used rivets to rive the parts together. With the progress of the times, there are more and more types of rivets, but traditional rivets have connection strength. Insufficient problem, so a new rivet is needed to solve the above problem.
1. The taper of the reaming hole should be 90°. It should be guaranteed that it should be less than 90° rather than greater than 90°. This is a key trick. 2. If the thickness of the sheet metal is less than the thickness of the head of the countersunk head screw, you can replace the screw with a smaller size, or it is better to ream a smaller hole instead of reaming the hole to increase the diameter of the bottom hole and cause the parts to not be pressed tightly. 3. If there are multiple countersunk head screw holes on the part, it should be processed more accurately. Once it is drilled crookedly, it will be ugly to assemble, but as long as the error is not large, it can be tightened completely, because when tightening, if the diameter of the screw is not very large. Large (about no more than 8mm), when there is an error in the hole distance, the screw head will be deformed due to the force when it is tightened or it will be tightened.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: screws with holes, cross head screws and bolts, hexagon screws, cylindrical positioning pins and other products, we can provide you with suitable fasteners for you solution.