bolts and screws
A bolt is essentially cylindrical, again with a helical ridge, and has a broad head usually shaped to take a spanner or wrench. It is used in conjunction with a nut, a member containing a pre-threaded hole into which the bolt fits. The objects to be fastened are held together by the pressure of the bolthead on one side, the nut on the other. The distance between consecutive turns of a screw thread is termed the pitch of the thread.
Related category• TOOLS
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