Which simple machine is used to hold two pieces of material together?

The screw is a simple machine that is specifically designed to hold two pieces of material together. It functions by converting rotational motion into linear motion, allowing it to be driven into materials such as wood, metal, or plastic. The helical thread of the screw exerts a force when it is twisted, pulling the materials together and creating a secure connection. This property of screws makes them highly effective for joining items together in construction and other applications.

While inclined planes, levers, and wedges have their unique functions, they do not serve the direct purpose of fastening materials together in the same way that screws do. Inclined planes are used to make lifting easier by allowing objects to be raised or lowered over a distance. Levers are utilized to amplify force to lift or move loads. Wedges, on the other hand, are used to separate or cut materials apart rather than join them. Thus, the screw is the ideal example of a simple machine for holding two pieces of material together effectively.