Do you know why screws are always tightened clockwise to the right?
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The English word for screw is Screw. The meaning of this word has changed considerably over the past few hundred years; at least by 1725, it meant “to mate”. Beyond the scholarly meaning in its name, the little screw has gone through thousands of years since its invention, until it was standardized to be tightened clockwise and loosened counter-clockwise. https://img.mp.itc.cn/upload/20170508/cc2a8167dac0479ba4eef8aacd840525_th.png Whether it’s screws, bolts, or other threaded connections, there are two types: left-hand threads and right-hand threads. Let’s first talk about where left-handed threads are used. In some areas where there is high-speed rotation to the right, left-handed screws are necessary, because during clockwise rotation, right-handed screws may loosen, while left-handed screws will become tighter. For example, the screws used to secure the grinding wheel on a grinder are left-hand screws ； Bicycle pedal spindle screw ； Places that require right-hand rotation*—such as the machine tool feed screws—are all equipped with left-hand screws. https://img.mp.itc.cn/upload/20170508/30f2ca69719149d2b4ee3697e7e56647.png The screws that we use frequently, whether in mechanical equipment or in everyday life, are generally tightened by turning them to the right. What is the principle behind this design? Is there any logic to it? In fact, there are two main reasons for designing most right-hand threads in this way: 1. It is based on principles of ergonomics; the direction of velocity with respect to the axis of rotation follows the right-hand rule. Since over 90% of people are right-handed, this design makes it easier for the majority to use them. https://img.mp.itc.cn/upload/20170508/82a0518c13b64ad58fb730e903589619_th.png2. The right-hand thread machining process is convenient, especially for turning large threads. https://img.mp.itc.cn/upload/20170508/5ba643f33a82421aaa1aa80fe375205e_th.png If conditions permit, you can also try using screws and turning them counterclockwise to see if it’s possible to do so. Give it a try yourself to see whether they tighten when turned clockwise as well
*It’s just a matter of habit and the general interchangeability of materials. There are more right-handed people; when you use your right hand to apply pressure downward, it’s used to tighten bolts, so why can’t you use upward motion as a way to tighten them? Lifting upward is more effective than pressing down with weight. It is easy to process; the equipment is designed to serve people – it can be configured in whatever direction is desired, and then rolled out accordingly.
It might have started as a *habitual issue, but later it was probably due to considerations of standardization and interchangeability.
Left-hand threads are simply against human logic^_^; it’s actually a matter of convention. For high-speed rotating equipment, we mainly consider the stress conditions when it comes to the rotation direction of threads, and there are quite a few left-hand threads^_^. In fact, lathe machining is just as convenient!
Rightward movement also implies good fortune; sometimes, the crosshatching of all components points upward, symbolizing positivity.
You are at the master level; your popularity is at its peak
Where there is a positive, there is a negative; when used together, the other one must be in the lower left corner – how sad!