A grindstone, also known as grinding stone, is a sharpening stone used for grinding or sharpening ferrous tools, used since ancient times. Tools are sharpened by the stone's abrasive qualities that remove material from the tool through friction in order to create a fine edge. In Australia, Aboriginal...
A grindstone, also known as grinding stone, is a sharpening stone used for grinding or sharpening ferrous tools, used since ancient times. Tools are sharpened by the stone's abrasive qualities that remove material from the tool through friction in order to create a fine edge. In Australia, Aboriginal peoples created grinding grooves by repeated shaping of stone axes against outcrops of sandstone. Grindstones have been used since ancient times, to sharpen tools made of metal. The working edge of the hatchet or axe was sharpened by rubbing it against an abrasive stone, eventually leading to the creation of a shallow oval-shaped groove over time, The grooves vary in length from 80 mm up to 500 mm , and can be up to 200 mm wide and 100 mm deep. They are often found near water, which was sprinkled on the stone during grinding to reduce dust. Grindstone machines work by spinning a circular piece of stone around its center point. The earliest known representation of a rotary grindstone, operated by a crank handle, is found in the Carolingian manuscript known as the Utrecht Psalter. The Luttrell Psalter, dating to around 1340, describes a grindstone 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. This tool article is a stub.