THE NUT AND BOLTS OF MODERN LIFE

 

  "The humble screw thread may simply be an inclined plane wrapped around a cylinder, but without it, metaphorically and literally, the wheels would come off the modern world.  Nature barely uses the concept, but for mankind it holds false teeth in place, focuses microscopes, and fastens hatches onto spacecraft.  Screw threads also provide the precision movement that allows the automated manufacture of just about every piece of technology we take for granted.  Without the screw thread our world would be a very different place" -Jem stansfield.
     The 'screw threads' is so called because the ridge spiraling down the body of the screw is known as the thread.
the functions of 'thread';
1. Converts rotational motion into linear motion.
2. It fastens two things.
3. It amplifies motion as in micrometer.
    The tightening of a fastener's screw thread is comparable to driving a wedge into a gap until it sticks fast through friction and slight elastic deformation.  Example for fasteners are wood screws, machine screws, nuts and bolts, also connecting threaded pipes.
    In car jack, rotatory motion is converted into linear motion. The "thread' is used in gears also.
    In micrometer screw, tiny linear motion is amplified by rotatory motion.  10 rotations may be required to move 1 mm distance.
   "Welding joins objects permanently, where as screws are adjustable.  Adhesive manufacturers may claim to have made nails redundant, but 'No more nuts-and - bolts' is a product,  I cannot see happening" - Stanhield.

    Long back, Archimedes screw was used to lift water as we see in the picture.
     "A ridge wrapped around a cylinder or cone in the form of a helix",  will stay for long time.
     A simple invention gets a paramount importance in our life. 
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