ASTM_D_2131_-_22.pdf

Designation:D213122Standard Classification forNatural Muscovite Mica Splittings1This standard is issued under the fixed designation D2131;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This classification covers the determination of musco-vite mica splittings of standard commercial grades and speci-fies the maximum allowable physical defects for each grade.Itis applicable to commercially available natural muscovite micasplittings regardless of the basic color of the mica or its source.1.2 The values stated in inch-pound units are to be regardedas the standard.The values given in parentheses are forinformation only.1.3 This standard is very similar to ISO 6386.It is expectedthat materials would be classified identically using the criteriaof either standard.The grades shown under“ASTM GradeNo.”in Table 1 and Table 2 are shown under“Old Grade No.”in ISO 6386-1981.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D351 Classification for Natural Muscovite Block Mica andThins Based on Visual QualityD1711 Terminology Relating to Electrical Insulation2.2 ISO Publications:ISO 6386-1981 Muscovite Mica SplittingsGrading andVisual Classification33.Terminology3.1 For definitions relating to mica and for terms applicableto this standard,refer to Terminology D1711,and Classifica-tion D351.4.Classification4.1 Mica splittings are classified by size,form,and visualquality and properties.4.2 Thirteen grades,based on size and form,are describedas given in Table 1.4.3 Within the grades,up to thirteen categories of visualquality are able to be separately specified,as listed in Section6.Not all of the visual quality categories are available in allgrades.5.Physical Properties5.1 Natural muscovite mica splittings shall meet the sizerequirements specified in Table 1.Classification D351,Table 1and Fig.1,define more completely the areas and minimumdimensions that define the size grades,and which are to beused in conjunction with Table 1 of this classification.5.2 There shall not be more than the maximum allowabletotal defects specified in Table 2 based on percentage weight.Such defects shall not lie predominantly in any one category.5.3 There shall not be more of any single defect than thepercentages specified where a specific percentage is allowedfor such defect.5.4 There shall not be any foreign matter included amongthe splittings.6.Visual Quality6.1 Where specified,the visual quality shall conform to thedescription of the visual category specified,as given inClassification D351:6.1.1 V-1Clear,6.1.2 V-2Clear and Slightly Stained,6.1.3 V-3Fair Stained,6.1.4 V-4Good Stained,6.1.5 V-5Stained A Quality,6.1.6 V-5.1Stained D351 Quality,6.1.7 V-6Stained B Quality,6.1.8 V-7Heavy Stained,1This classification is under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.01 on Electrical Insulating Products.Current edition approved May 1,2022.Published May 2022.Originallyapproved in 1962.Last previous edition approved in 2016 as D2131 97(2016).DOI:10.1520/D2131-22.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1TABLE 1 Requirements for Size and Average Thickness of SplittingsNOTE1Splittings shall not be of the minimum area specified,but shall contain a fair proportion of sizes throughout the range specified.NOTE2The areas specified do not refer to the total area of the splittings but to the usable rectangular size that each grade will produce.For example,Grade 5 splittings shall be large enough to provide rectangular pieces measuring 112by 2 in.,3 by 2 in.,2 by 213in.,etc.ASTM GradeFormSize,in.2AMinimumDimension of Us-ableRectangle,in.BThickness of 10Splittings,in.B4Bookform6 to 10,ex