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  • Category: Miscellaneous

    Why are screws right handed?

    We tighten the screws often whenever we find them loose in our appliances or furniture or any other utility item in our household and once we tighten them up, it helps to make the item more sturdy and usable. Have you ever wondered as why we tighten them in a clockwise direction. Even the cap or lid of a bottle, we rotate it in a clockwise direction to close it. The answer lies in the working of our hands. If we observe, using our right hand, we can rotate a screw driver more easily in a clockwise direction than in the anti clockwise direction. Same thing happens when we close the cap of a bottle. That is the main reason why the screws are designed in that way and the thread on the screws are engraved accordingly. Only problem will be that a left handed person might not feel comfortable with this but as most of the people are right handed, the most used and versatile item called screw evolved in that way only.
    In some machines due to the technical reasons and requirements sometimes a few left handed screws are also used but that is a rare thing. In such cases most of the screws will be right handed except a few which are intentionally kept left handed. So, if there is such a left handed screw in some machine and someone is trying to open it in the usual way not knowing that it is a specifically fitted left handed screw then he will be actually tightening it more and more!
    All the nut-bolts and other big sized screws etc are right handed which are used in various industries for different purposes. The big sized bolts are known as fasteners also.

    This is my entry for the month end topic based TOW contest - Right.
  • #733005
    Answer is very simple. Since the threads on the screws are generally on the right motion during the manufacture, the screws are tightened to the the right side. If the screws are made of left hand motion, it would be tightened to the left side. At times, due to the motion of the object to the forward or rear, the threads of the bolts and nuts are made accordingly.
    No life without Sun

  • #733013
    What I feel that we have been habituated through the clock wise direction for any matter and thus even screws are made with ridges to turn right and fit into the groove. But there are some exceptions too. For example the ear rings or the studs with screws turns anti clockwise to fit. Nevertheless it does not matter to us which way the screws are turning to get fit. What we need is the right screw and right fitting. Often the screws of pressure cooker gets into loose mode and we need to tight but the threads gets loosen for the heat of the cooker and the screws get into rusted mode.
    K Mohan @ Moga
    'Idhuvum Kadandhu Pogum "
    Even this challenging situation would ease

  • #733030
    The screws, nuts and bolts are created by human beings only. Whatever we do we will see that the item will be useful and they can use it conveniently. We always work for our convenience. So rotating the screwdriver towards the right is always convenient to the majority of human beings. That is why they are designed like that. Many machines and tools are designed in such a way that people can use them very conveniently without any problem.
    A good presentation by the author for the TOW contest using the word Right.

    always confident

  • #733036
    Most people are born right-handed. They do all the work that needs to be done with the right hand. The easiest way is to turn the right hand clockwise. Rotating anti-clockwise with the right hand is very difficult and difficult to make the screws tight. That is why all the screws are right-handed. But for those who are more capable of the left hand than the right hand, it is a little harder to tighten the screws. They are easy to unscrew the screws, and such people are a few in the world.
    "Cheruthulli Peruvellam"
    small drops make a mighty ocean

  • #733046
    Mohan, you have given a very nice example of the left hand screw used in ear rings or ear studs. Yes, there are some exceptions like that.
    Knowledge is power.

  • #733105
    I have never noted that though in the household work we open the bottle caps so many time and close them in the usual right hand way. Then if something becomes loose especially a screw in idli stand or other utility item we simply tighten it in clockwise direction and that is all.
    Thoughts exchanged is knowledge gained.

  • #733141
    Interesting observation and a good explanation provided in this thread. All the developments took place for our convenience and design is also a very important factor because one has to repair the device if something is wrong with it. Keeping this in mind, screws are made so that the repairer/manufacturer doesn't face any difficulty while opening the device.

    "Life is easier when you enjoy what you do"

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