"Set Square" wrote in message ...
Are you talking about woodscrews, or parallel-sided machine screws? If the
latter, the trick is to screw a nut onto the screw *before* shortening it.
Then cut it to length with a hacksaw. Then file the end as flat as you can.
Finally unscrew and remove the nut. As it passes the cut end, it will clean
up the threads.

can I hacksaw and file a nylon screw? if not, then how would I shorten it?

thanks