Berkel 01-400825-00122

SHARPENER COVER SCREW

A screw is a type of fastener, in some ways similar to a bolt typically made of metal, and characterized by a helical ridge, known as a male thread (external thread). Screws are used to fasten materials by digging in and wedging into a material when turned, while the thread cuts grooves in the fastened material that may help pull fastened materials together and prevent pull-out.

A screw drive is a system used to turn a screw. At a minimum, it is a set of shaped cavities and protrusions on the screw head that allows torque to be applied to it. Usually, it also involves a mating tool, such as a screwdriver, that is used to turn it. Other examples include Phillips head screws and screwdrivers, and Allen hex screws and wrenches.

Knife and blade sharpening is the process of making a knife or similar tool sharp by grinding against a hard, rough surface, typically a stone, or a flexible surface with hard particles, such as sandpaper.  Grinding is generally done with some type of sharpening stone. Sharpening stones come in coarse and fine grits and can be described as hard or soft based on whether the grit comes free of the stone with use.