Editing Pencil (section)

=== Pencil hardness test ===
Graded pencils can be used for a rapid test that provides relative ratings for a series of coated panels but can't be used to compare the pencil hardness of different coatings. This test defines a "pencil hardness" of a coating as the grade of the hardest pencil that does not permanently mark the coating when pressed firmly against it at a 45 degree angle.<ref>This testing method is approved by the [[International Organization for Standardization|ISO]] as standard ISO 15184:1998 Paints and varnishes – Determination of film hardness by pencil test [https://www.iso.org/standard/55329.html?browse=tc ISO.org] {{webarchive|url=https://web.archive.org/web/20171026111219/https://www.iso.org/standard/55329.html?browse=tc |date=26 October 2017 }}. See [http://www.pra-world.com/technical/testingphysicalhardness.htm pra-world.com]  {{webarchive|url=https://web.archive.org/web/20070929224302/http://www.pra-world.com/technical/testingphysicalhardness.htm |date=29 September 2007 }} for a description of the test. Unfortunately the hardness of pencils is not standardised. For this reason the standard specifies various brands of pencils that are to be used in this test.</ref><ref>
{{Cite journal
 |author      = Mac Simmons
 |title       = The Pencil Hardness Test
 |journal     = Woodwork
 |date        = April 2000
 |page        = 76
 |url         = http://www.pencilpages.com/articles/simmons.htm
 |accessdate  = 13 September 2007
 |deadurl     = no
 |archiveurl  = https://web.archive.org/web/20070928042339/http://www.pencilpages.com/articles/simmons.htm
 |archivedate = 28 September 2007
 |df          = dmy-all
}}</ref> For standardized measurements, there are [[Mohs hardness]] testing pencils on the market. <!-- Sorry, no ref. A Google search shows many brands, such as http://mahavirgems.in/Gem-Hardness-Pencils-1-to-10-on-Moh's-Scale, but I couldn't find an overarching discussion. -->

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