grindstone

Grindstones have been used since ancient times, to sharpen tools made of metal. They are usually made from sandstone.{{Citation|title=Grindstones |url=http://scholar.chem.nyu.edu/tekpages/grindstone.html |access-date=2010-02-10 |archive-url=https://web.archive.org/web/20060117023109/http://scholar.chem.nyu.edu/tekpages/grindstone.html |archive-date=2006-01-17 |postscript=. |url-status=dead }}{{Citation | last = Knight | first = Edward Henry | title = Knight's American mechanical dictionary | pages = 1022–1023 | publisher = Houghton, Mifflin | year = 1876 | url = https://books.google.com/books?id=7jZVAAAAMAAJ&pg=PA1022 | postscript =.}}

File:KingsTableland1.JPG, New South Wales, Australia]]

Aboriginal grinding grooves, or axe-grinding grooves, have been found across the Australian continent.{{cite web | title=Fact sheet: Aboriginal axe-grinding grooves| website=First Peoples – State Relations| publisher= Victorian Government| url=https://www.firstpeoplesrelations.vic.gov.au/fact-sheet-aboriginal-axe-grinding-grooves | access-date=21 October 2021}} 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,{{cite web| url=https://www.environment.act.gov.au/__data/assets/pdf_file/0006/696480/Public-Background-Information-Molonglo-Grinding-Grooves-ENDORSED-HCM-20150604.pdf| title=Background information: Molonglo Valley Grinding Grooves | author= ACT Heritage Council| date=June 2015 | access-date=21 October 2021 }} The grooves vary in length from {{cvt|80|mm}} up to {{cvt|500|mm}}, and can be up to {{cvt|200|mm}} wide and {{cvt|100|mm}} deep. They are often found near water, which was sprinkled on the stone during grinding to reduce dust.

File:Finch Foundry, grindstone.jpg.[http://www.phrases.org.uk/meanings/217200.html The meaning and origin of the expression: Keep your nose to the grindstone] at The Phase Finder.]]

Grindstone machines work by spinning a circular piece of stone around its center point. These machines usually have pedals for speeding up and slowing down the stone to control the sharpening process. The earliest known representation of a rotary grindstone,{{harvnb|White|1962|p=110}} operated by a crank handle, is found in the Carolingian manuscript known as the Utrecht Psalter. This pen drawing from about 830 goes back to a late antique original.{{harvnb|Hägermann|Schneider|1997|pp=425f.}} The Luttrell Psalter, dating to around 1340, describes a grindstone rotated by two cranks, one at each end of its axle.{{harvnb|White|1962|p=111}} Around 1480, the early medieval rotary grindstone was improved with a treadle and crank mechanism.{{harvnb|White|1962|p=167}}

• Lathe
• Millstone
• Punch (tool)
• Grindstone City Historic District

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{{Commons category|Grinding stones}}

• {{Citation

| last = Hägermann

| first = Dieter

| last2 = Schneider

| first2 = Helmuth

| title = Propyläen Technikgeschichte. Landbau und Handwerk, 750 v. Chr. bis 1000 n. Chr.

| place = Berlin

| edition = 2nd

| year = 1997

| isbn = 3-549-05632-X

}}

• {{Citation

| last = White

| first = Lynn Jr.

| author-link = Lynn Townsend White Jr.

| title = Medieval Technology and Social Change

| place = Oxford

| year = 1962

| publisher = At the Clarendon Press

}}

{{Woodworking}}

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{{DEFAULTSORT:Grindstone (Tool)}}

Category:Woodworking

Category:Grinding and lapping

Category:Knives

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