There’s actually wood screws, machine screws and sheet metal screws
Wood screws are tapered and have relatively coarse threads. Of course they screw into wood, preferably with a pilot hole but not prethreaded.
Machine screws have precision threading and straight threads and screw into precise matching drilled and tapped (threaded) holes.
Sheet metal screws have finer threads than wood screws but are tapered a bit at the point and are intended to self thread into holes drilled in thin sheet metal.
The below illustration also shows self-tapping machine screws, a variation on machine screws - they have a formed tip that starts and cuts threads in unthreaded holes of the right size, matching the screw’s threads.
There are endless varieties of drive heads and these can be applied across the different thread types as well.
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Answer:
There’s actually wood screws, machine screws and sheet metal screws
Wood screws are tapered and have relatively coarse threads. Of course they screw into wood, preferably with a pilot hole but not prethreaded.
Machine screws have precision threading and straight threads and screw into precise matching drilled and tapped (threaded) holes.
Sheet metal screws have finer threads than wood screws but are tapered a bit at the point and are intended to self thread into holes drilled in thin sheet metal.
The below illustration also shows self-tapping machine screws, a variation on machine screws - they have a formed tip that starts and cuts threads in unthreaded holes of the right size, matching the screw’s threads.
There are endless varieties of drive heads and these can be applied across the different thread types as well.