What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Therefore, in some cases, workers use a fixed torque wrench to control the tightening degree of the nut, but the fixed torque wrench is not convenient to use, and it needs to be checked frequently. At the same time, because the fixed torque wrench is not a conventional tool, its price is relatively high, which It also leads to its high procurement cost, and frequent verification also makes the later use cost also high.
The tie rod and joint of the high-voltage isolating switch are often connected by driving an elastic cylindrical pin into the connecting pin hole. The traditional assembly method is to prevent the tie rod and joint from the V-block, and hold the elastic cylindrical pin to align the connecting pin hole. Then hit it with a hammer. Since the elastic cylindrical pin is small, it is easy to injure people's hands by adopting this assembly method, and at the same time, the elastic cylindrical pin is not positioned accurately, which causes large assembly errors and low assembly efficiency.
Countersunk head screws are mostly used after installation, and the surface of the parts cannot be raised, and the parts to be fastened have two thicknesses. Thickness, after the screw is tightened, there is still a part of the screw thread that does not enter the threaded hole. In this case, the countersunk head screw can definitely be tightened. There is usually a situation where the thickness of the fastened part is less than the height of the head of the countersunk head screw, which is commonly seen in sheet metal parts in mechanical equipment, such as the connection between the hinge of the chassis and the door and the box; the sheet metal of the equipment The connection of the cover to the equipment, etc. Due to the small thickness of the part, the tightened sheet metal part, the screw through hole completely becomes a conical hole, in this case, when the countersunk head screw is tightened, the screw head is not a tapered surface to press the sheet metal part , but the bottom of the screw head and the top of the threaded hole are squeezed. Although it feels that the screw is tightened, the sheet metal part is stuck instead of being pressed. In this case, although it feels that the screw is tightened, the sheet metal The gold pieces were indeed not tightened. This is a very common situation. Let’s talk about the reasons for the processing: the head cone of the countersunk screw has a 90° conical angle, and the apex angle of the newly bought drill is usually 118°-120°. Some workers who lack training do not know this angle is poor. It is often used to ream the hole with a 120° drill bit, which results in that when the countersunk head screw is tightened, it is not the conical surface of the head, but a line at the bottom of the screw head, which is one of the reasons why the so-called countersunk head screw cannot be tightened. , it's not the screw's fault.
With the advancement of technology in various industries, the current structural design of screws has evolved from just simple locking to focusing on work efficiency during the locking process and not destroying the integrity of the objects to be locked. New cases such as No. 556784 screw improvement and No. 289415 screw that integrates locking, stability, labor-saving, fast and multi-function which were previously designed and approved and published in the Central Taiwan Bulletin are the main representatives of screws. It is clear that It is learned that the two cases not only fully improve the shortcomings of the traditional simple locking screws, but also achieve the purpose of substantial improvement of the screws designed in each case in actual use.
The above content is uploaded by Yueluo or the Internet. If there is any copyright issue, please contact [email protected].
