Editing Pound (mass) (section)

== Current use <span class="anchor" id="international pound"></span> ==
The United States and the [[Commonwealth of Nations]] agreed upon common definitions for the pound and the [[yard]]. Since 1 July 1959, the [[International yard and pound|international avoirdupois pound]] (symbol lb) has been defined as exactly {{val|0.45359237|u=kg}}.<ref name="Standards1959">{{cite book|author=United States. National Bureau of Standards|author-link=National Institute of Standards and Technology|title=Research Highlights of the National Bureau of Standards|url=https://books.google.com/books?id=4aWN-VRV1AoC&pg=PA13|access-date=12 July 2012|year=1959|publisher=U.S. Department of Commerce, National Bureau of Standards|page=13}}</ref><ref>National Bureau of Standards, [http://physics.nist.gov/Pubs/SP447/app8.pdf Appendix 8] {{webarchive|url=https://web.archive.org/web/20090118111241/http://www.physics.nist.gov/Pubs/SP447/app8.pdf |date=18 January 2009 }}; National Physical Laboratory, P{{nbsp}}H Bigg ''et al.'' : ''[http://www.iop.org/EJ/abstract/0508-3443/13/9/305 Re-determination of the values of the imperial standard pound and of its parliamentary copies in terms of the international kilogramme during the years 1960 and 1961]''; Sizes.com: ''[http://www.sizes.com/units/pound_avoirdupois.htm pound avoirdupois] {{Webarchive|url=https://web.archive.org/web/20191024120334/http://www.sizes.com/units/pound_avoirdupois.htm |date=24 October 2019 }}.''</ref>

In the United Kingdom, the use of the international pound was implemented in the [[Weights and Measures Act 1963]].<ref>Quoted by Laws LJ in {{cite web|url=http://www.bailii.org/ew/cases/EWHC/Admin/2002/195.html|title=<nowiki>[2002] EWHC 195 (Admin)</nowiki>|access-date=12 August 2006}}</ref>

{{Blockquote|The yard or the [[metre]] shall be the unit of measurement of [[length]] and the pound or the [[kilogram]] shall be the unit of measurement of mass by reference to which any measurement involving a measurement of length or [[mass]] shall be made in the United Kingdom; and- <br />(a) the yard shall be 0.9144 metre exactly; <br />(b) the pound shall be {{gaps|0.453|592|37}} kilogram exactly.|''Weights and Measures Act'', 1963, Section 1(1)<ref name="vlex 1963">{{cite web |url=https://vlex.co.uk/vid/weights-and-measures-act-808389885 |title=Weights and Measures Act 1963 |publisher=vLex United Kingdom |access-date=17 April 2021 | date=31 July 1963}}</ref>}}

An [[avoirdupois]] pound is equal to 16 avoirdupois [[ounce]]s and to exactly 7,000 [[Grain (unit)|grain]]s. The conversion factor between the kilogram and the international pound was therefore chosen to be divisible by 7 with a [[terminating decimal]] representation, and an (international) grain is thus equal to exactly {{val|64.79891|ul=milligrams}}.

In the United Kingdom, the process of [[metrication in the United Kingdom|metrication]] and [[European units of measurement directives]] were expected to eliminate the use of the pound and ounce, but in 2007 the European Commission abandoned the requirement for metric-only labelling on packaged goods there, and allowed for dual [[metric system|metric]]–[[imperial units|imperial]] marking to continue indefinitely.<ref>{{cite news |url=http://news.bbc.co.uk/1/hi/uk/6988521.stm |title=EU gives up on 'metric Britain |work=BBC News |access-date=4 May 2015 |date=11 September 2007}}</ref><ref>{{cite news|title=Will British people ever think in metric?|url=https://www.bbc.co.uk/news/magazine-16245391|publisher=BBC|access-date=4 May 2015|date=21 December 2011|first1=Jon|last1=Kelly}}</ref>

In the United States, the [[Metric Conversion Act|Metric Conversion Act of 1975]] declared the metric system to be the "preferred system of weights and measures" but did not suspend use of [[United States customary units]], and the United States is the only industrialised country where commercial activities do not predominantly use the metric system,<ref name="World Factbook">
{{cite book
  | url        = https://www.cia.gov/library/publications/the-world-factbook/appendix/appendix-g.html
  | archive-url = https://web.archive.org/web/20070613023743/https://www.cia.gov/library/publications/the-world-factbook/appendix/appendix-g.html
  | url-status = dead
  | archive-date = 13 June 2007
  | title      = The World Factbook
  | date       = 17 January 2007
  | publisher  = [[Central Intelligence Agency]]
  | chapter    = Appendix G – Weights and Measures
  | access-date = 4 February 2007
}}</ref> despite [[metrication in the United States|many efforts to do so]], and the pound remains widely used as one of the key customary units.<ref>{{cite web | title=US 1988 law on metrification |url=https://www.law.cornell.edu/cfr/text/48/611.002-70 |access-date=21 September 2019}}</ref><ref>{{cite web|title=Countries not using SI |date=22 March 2011 |url=https://www.zmescience.com/other/map-of-countries-officially-not-using-the-metric-system/ |access-date=21 September 2019 }}</ref>