Knife Sharpener : Kitchen Tools
There are various kinds of knife sharpeners available for maintaining the sharpness of knives.
A sharpening stone or oil stone is also known simply as a stone, and is a tool for maintaining the sharpness of knives. It consists of a carborundum stone, a block of ceramic, or a metal plate with embedded diamond dust. Many of these require the addition of an appropriate lubricant, such as oil or water to prevent damage to the stone.
For maintaining the edge on a knife, and not for intensive sharpening, is the sharpening steel, otherwise known simply as a steel. It usually consists of a hardened steel rod with many tiny grooves scored lengthwise. Seemingly paradoxically, they can also be made from a ceramic material specifically intended for sharpening hardened knives, as a standard steel can quickly become blunted. Another version is the diamond steel, with tiny specks or industrial diamond dust bonded to its surface. These are very effective for both sharpening and honing the edges of knives, but they tend to wear away at the knife far more quickly than other kinds of steel. To use a steel, the knife is drawn across roughly perpendicular to it, and at the appropriate angle for the knife.