Sharpening

Sharpening is the process of creating or refining a sharp edge of appropriate shape on a tool or implement designed for cutting. Sharpening is done by grinding away material on the implement with an abrasive substance harder than the material of the implement, followed sometimes by processes to polish the sharp surface to increase smoothness and to correct small mechanical deformations without regrinding.

Tools and materials for sharpening

There are a wide variety of ways of sharpening tools. Malleable metal surfaces such as bronze, iron and mild steel may be formed by beating or peening a flat surface into a sharp edge which incidentally causes work hardening.

More commonly, an abrasive material may be rubbed against the cutting edge to be sharpened. The most traditional material is a natural stone such as sandstone or granite, but modern synthetic grinding wheels and flat sharpening stones can be manufactured in precise grades of abrasiveness according to the intended process. Finally, a sharp edge may be 'dressed' using a Honing steel