A woodworking knife sharpener is a machine or tool used to restore and maintain the sharp cutting edges of woodworking blades such as planer knives, chisels, and jointer blades. It typically consists of a motor, a rotating grinding wheel or abrasive belt, a blade holding clamp or guide, and an adjustable angle mechanism to ensure precise sharpening. Some advanced models also include a cooling system (water or oil) to prevent overheating and preserve the hardness of the blade. These machines are essential in carpentry workshops and timber processing industries to maintain clean, accurate cuts and improve work efficiency.

In operation, the blade is securely fixed in the holder at the required sharpening angle. When the machine is switched on, the grinding wheel or abrasive surface rotates at high speed. The operator then carefully brings the blade into contact with the grinding surface, allowing it to remove small amounts of metal and reshape the cutting edge. The angle guide ensures consistency along the entire blade length. If a cooling system is present, it continuously cools the blade to avoid damage from heat. This process is repeated until the blade achieves a sharp, smooth edge, after which it may be lightly honed or polished for a finer finish before reuse.