- Screw (simple machine)
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of the machine. More threading increases the mechanical advantage. A rough comparison of mechanical advantage can be done by taking the circumference of the shaft of the screw and divide by the distance between the threads.
A screw is a shaft with a helical groove or thread formed on its surface and provision at one end to turn the screw. Its main uses are as a threaded fastener used to hold objects together, and as a simple machine used to translate torque into linear force. It can also be defined as an inclined plane wrapped around a shaft. Screws come in a variety of shapes and sizes for different purposes.
The mechanical advantage of a screw without using a screwdriver is:
*P = Pitch of screw (The distance between two adjacent screw threads is called the pitch.)
*C = Circumference of the head
The same formula can be used when using a screwdriver, but with:
*C = Circumference of the screwdriver handle.
Lead screwand ball screware specialized screws for translating rotational to linear motion.
* Automated garage door, where a motor drives a long finely threaded shaft at relatively high speed and lifts the heavy door at a slower rate.
Archimedes' screws and worm gears are examples of this machine.
Screw- the threaded fastener
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