Editing Bow drill

{{short description|Drilling tool of prehistoric origin operated by the cord of a bow}}

A '''bow drill''' is a simple hand-operated type of [[tool]], consisting of a rod (the ''spindle'' or ''drill shaft'') that is set in rapid rotary motion by means of a cord wrapped around it, kept taut by a [[bow and arrow|bow]] which is pushed back and forth with one hand. This [[tool]] of prehistoric origin has been used both as a [[drill]], to make holes on solid materials such as [[wood]], [[stone]], [[bone]], or [[teeth]], and as a [[fire drill (tool)|fire drill]] to [[Fire making#Friction|start a fire]].<ref name=hodge2003/><ref name=ulrich2007/><ref name=garg2012/>

[[File:Bow Drill with annotations.svg|thumb|An image of a wooden bow drill designed for fire starting]]

The spindle can be held into a fixed frame, or by a hand-held block (the ''hand piece'' or ''thimble'') with a hole into which the top of the shaft is inserted. Some [[lubricant]] should be used to reduce friction between these two parts, otherwise, it could lead to some trouble when doing it too fast. A popular campcraft book of 1920 attributed this invention to the [[Inuit]].<ref name=beard2014/> In [[Mehrgarh]] ([[Pakistan]]) it has been dated between the 4th-5th millennium BCE.<ref>{{cite book | first1 = Hermann | last1 = Kulke | first2 = Dietmar |last2 = Rothermund | title = A History of India | publisher = Routledge |date = 2004 |location = Abingdon, Oxfordshire |page = 22 |url = https://books.google.com/books?id=TPVq3ykHyH4C&q=Kulke,%20Hermann%20%26%20Rothermund,%20Dietmar%20(2004).%20%22A%20History%20of%20India%22%20bow%20drill%20MehrgarhE |doi = 10.4324/9781315628806 |isbn = 0415329205 }}</ref>

The string of the bow is wrapped once around the spindle, so that it is tight enough not to slip during operation. In a variation called the '''Egyptian bow drill''', the cord is wound around the shaft multiple times, or is fixed to it by a knot or a hole.{{citation needed|date=January 2021}}

The '''strap drill''' is a simpler version, where the bow is absent and the cord is kept taut by pulling the ends with both hands, while moving them left and right at the same time. In the absence of a frame, the thimble is shaped so that it can be held with the chin or the mouth.{{citation needed|date=January 2021}}

The bow lathe used for traditional [[woodturning]] uses the same principle as the bow drill.

== History ==
[[File:Feu-archet.jpg|thumb|Bow drill being used to make a fire.]]

Bow drills with [[jasper|green jasper]] bits were used in [[Mehrgarh]] between the 4th and 5th millennium BC to drill holes into [[lapis lazuli]] and [[carnelian]]. Similar drills were found in other parts of the [[Indus Valley civilization]] and [[Iran]] one millennium later.<ref name=kulke2004/>

==Usage as a fire drill==
For use as a [[Fire drill (tool)|fire drill]], the shaft should have a blunt end, which is placed into a small cavity of a stationary piece of wood (the ''fireboard'').  Turning the shaft with high speed and downward pressure generates heat, which eventually creates powdered [[charcoal]] and ignites it forming a small [[ember]].<ref name=beard2014/>

For drilling, the lower end of the spindle may be fitted with a hard [[drill bit]] that creates the hole by [[abrasive|abrasion]] or cutting.{{citation needed|date=January 2021}}

== See also ==
* [[Brace (tool)]]
* [[Pump drill]]

== References ==
<references>

<ref name=kulke2004>Kulke, Hermann & Rothermund, Dietmar (2004). ''A History of India''. Routledge. 22. {{ISBN|0-415-32920-5}}.</ref>

<ref name=beard2014>{{cite book |last1=Beard |first1=Daniel |author-link=Daniel Carter Beard |title=Camp-Lore and Woodcraft |date=2014 |orig-year=1920 |publisher=Courier Corporation |isbn=978-0-486-80079-0 |url=https://books.google.com/books?id=iDOlBQAAQBAJ }}</ref>

<ref name=ulrich2007>{{cite book|author=Roger Bradley Ulrich|title=Roman Woodworking|url=https://books.google.com/books?id=DDh5yOgfnuoC&pg=PA30|year=2007|publisher=Yale University Press|isbn=978-0-300-10341-0|pages=30–}}</ref>

<ref name=garg2012>{{cite book|author1=Nisha Garg|author2=Amit Garg|title=Textbook of Operative Dentistry|url=https://books.google.com/books?id=WredzxNmeUMC&pg=PA103|date=30 December 2012|publisher=JP Medical Ltd|isbn=978-93-5025-939-9|pages=103–}}</ref>

<ref name=hodge2003>{{cite book|author=Frederick Webb Hodge|title=Handbook of American Indians North of Mexico V. 1/4|url=https://books.google.com/books?id=WmQgh7i-LdQC&pg=PA402|date=1 July 2003|publisher=Digital Scanning Inc|isbn=978-1-58218-748-8|pages=402–}}</ref>

</references>

==External links==
{{Sister project links|auto=y}}
{{Wikibooks|Backpack Camping and Woodland Survival/Skills/Fire/Fire Starting/Bow Drill}}
* [http://www.primitiveways.com/e-fire.html The Egyptian Bow Drill]
* [http://www.wildwoodsurvival.com/survival/fire/bowdrill/men73/index.html Information on constructing and using a hand drill]

{{Firelighting}}
{{Woodworking}}
{{Prehistoric technology}}

[[Category:Mechanical hand tools]]
[[Category:Woodworking hand tools]]
[[Category:Fire making]]
[[Category:Inventions of the Indus Valley Civilisation]]