What is the opposite of stop?

What is this called?

any of several types of strong screws threaded to receive a nut and used to hold things together.

What is the opposite of off?

a cord of metal wire used to carry electrical power, etc.

a tool for cutting, usually a thin blade of metal with sharp teeth.

a wrench having a curved head with a hook or pin at one end for engaging notches or holes in collars, etc.

a block, usually of metal, made with a threaded hole so that it can be screwed down on a bolt to hold together objects through which the bolt passes.

a metal tool like a wedge with a cutting edge at the end of the blade, used for cutting or shaping wood, stone, etc.

a thin, rod-shaped piece of metal, usually having a pointed tip and a flattened head, made to be hammered into wood or other material as a fastener or support.

What is the opposite of tighten?

a hand tool for turning a screw, consisting of a handle attached to a long, narrow shank, usually of metal, which tapers and flattens out to a tip that fits into the slotted head of a screw.

a flat ring used under a bolt to give tightness to a joint, prevent leakage, etc.