Grindstone

This article is about the metalworking tool. For other uses, see Grindstone (disambiguation).

File:Francisco de Goya y Lucientes 008.jpg

Man using a portable grindstone; painting by Goya

File:Finch Foundry, grindstone.jpg

Large waterwheel powered grindstone. The user would lie on the plank above the grindstone while grinding metal items, giving rise to the phrase nose to the grindstone.

A grindstone is a round sharpening stone used for grinding or sharpening ferrous tools. They are usually made from sandstone.

Grindstone machines usually have pedals in which to speed and slow the stone to sharpen metal to the point of perfection.

A rotary grindstone − the earliest representation thereof, which is operated by a crank handle, is shown in the Carolingian manuscript Utrecht Psalter; the pen drawing from about 830 goes back to a late antique original. The Luttrell Psalter, dating to around 1340, describes a grindstone which was rotated by two cranks, one at each end of its axle. Around 1480, the early medieval rotary grindstone was improved with a treadle and crank mechanism.

See also

• Lathe
• Millstone
• Punch (tool)