ASTM D351-18
(Classification)Standard Classification for Natural Muscovite Block Mica and Thins Based on Visual Quality
Standard Classification for Natural Muscovite Block Mica and Thins Based on Visual Quality
SIGNIFICANCE AND USE
4.1 The properties included in this standard are those required to control the visual quality, usable area, thickness, hardness, and stiffness.
SCOPE
1.1 This classification covers the determination of commercially available natural muscovite block mica and is intended to be independent of the basic color of the mica or its source.
1.2 Muscovite mica is characterized by having an optical axial angle between 50 and 75° (see Appendix X1); and has a weight loss when heated for 5 min at 600°C not exceeding 0.2 % (based on the weight after drying at 120°C).
1.3 The visual system of classifying the quality of natural muscovite mica covered by this specification is based upon relative amounts of visible foreign inclusions such as air bubbles, stains, and spots in combination with relative amounts and types of waviness, as well as other physical properties. In this system, a perfectly clear, transparent, flat specimen of mica is the visual standard of perfection. Increasing amounts of visual defects lower the visual quality, and a total of 13 levels of visual quality are covered by this standard. This method of classification, generally known as the Bengal India System, is purely qualitative and is entirely dependent on personal opinion and judgment.
1.4 The standards for visual quality classification that are covered in this classification are the best commercially available concept of the various qualities and their relative positions. Variations in the methods of using and applying these standards from those herein defined are specified by the purchaser, or defined by agreement between the supplier and the purchaser.
1.5 Standard size classifications are defined, based upon available usable rectangular areas and the minimum dimensions of the rectangles that the pieces will yield. Precautions to be taken in making thickness measurements are also described.
1.6 This standard covers the following two definite forms of commercial preparation:
1.6.1 Form 1—Full-trimmed natural block mica, 0.007 in. (0.178 mm) minimum thickness.
1.6.2 Form 2—Partially-trimmed natural block mica, 0.007 in. minimum thickness.
1.7 The basic color of mica, such as white, ruby, light green, dark green, brownish green, and rum, as well as other colors, and the method of controlling the color and other problems associated with the basic color, are not a part of this classification.
1.8 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.9 Section 5 is technically identical to procedures specified in ISO 67-1981.
1.10 Section 6 differs somewhat in procedure from ISO 5972-1978, but data obtained by either is expected to be identical.
1.11 Section 7 is technically identical to procedures specified in ISO 2185-1972.
1.12 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:D351 −18
Standard Classification for
Natural Muscovite Block Mica and Thins Based on Visual
1
Quality
This standard is issued under the fixed designation D351; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 1.6.1 Form 1—Full-trimmed natural block mica, 0.007 in.
(0.178 mm) minimum thickness.
1.1 This classification covers the determination of commer-
1.6.2 Form 2—Partially-trimmed natural block mica, 0.007
ciallyavailablenaturalmuscoviteblockmicaandisintendedto
in. minimum thickness.
be independent of the basic color of the mica or its source.
1.2 Muscovite mica is characterized by having an optical 1.7 Thebasiccolorofmica,suchaswhite,ruby,lightgreen,
axial angle between 50 and 75° (see Appendix X1); and has a
dark green, brownish green, and rum, as well as other colors,
weight loss when heated for 5 min at 600°C not exceeding and the method of controlling the color and other problems
0.2 % (based on the weight after drying at 120°C).
associated with the basic color, are not a part of this classifi-
cation.
1.3 The visual system of classifying the quality of natural
muscovite mica covered by this specification is based upon
1.8 The values stated in inch-pound units are to be regarded
relative amounts of visible foreign inclusions such as air
as standard. The values given in parentheses are mathematical
bubbles,stains,andspotsincombinationwithrelativeamounts
conversions to SI units that are provided for information only
and types of waviness, as well as other physical properties. In
and are not considered standard.
thissystem,aperfectlyclear,transparent,flatspecimenofmica
1.9 Section 5 is technically identical to procedures specified
is the visual standard of perfection. Increasing amounts of
in ISO 67-1981.
visual defects lower the visual quality, and a total of 13 levels
of visual quality are covered by this standard. This method of
1.10 Section 6 differs somewhat in procedure from ISO
classification, generally known as the Bengal India System, is
5972-1978, but data obtained by either is expected to be
purely qualitative and is entirely dependent on personal opin-
identical.
ion and judgment.
1.11 Section 7 is technically identical to procedures speci-
1.4 The standards for visual quality classification that are
fied in ISO 2185-1972.
covered in this classification are the best commercially avail-
able concept of the various qualities and their relative posi- 1.12 This international standard was developed in accor-
dance with internationally recognized principles on standard-
tions. Variations in the methods of using and applying these
standards from those herein defined are specified by the ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
purchaser, or defined by agreement between the supplier and
the purchaser. mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.5 Standard size classifications are defined, based upon
available usable rectangular areas and the minimum dimen-
2. Referenced Documents
sions of the rectangles that the pieces will yield. Precautions to
2
be taken in making thickness measurements are also described.
2.1 ASTM Standards:
D374 Test Methods for Thickness of Solid Electrical Insu-
1.6 This standard covers the following two definite forms of
lation (Metric) D0374_D0374M
commercial preparation:
D1711 Terminology Relating to Electrical Insulation
1
This classification is under the jurisdiction of ASTM Committee D09 on
Electrical and Electronic Insulating Materials and is the direct responsibility of
2
Subcommittee D09.01 on Electrical Insulating Products. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2018. Published November 2018. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1932. Last previous edition approved in 2014 as D351 – 14. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D0351-18. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D351−18
2.2 ISO Publications: 4. Significance and Use
ISO 67-1981 Muscovite Mica Blocks, Th
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D351 − 14 D351 − 18
Standard Classification for
Natural Muscovite Block Mica and Thins Based on Visual
1
Quality
This standard is issued under the fixed designation D351; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 This classification covers the determination of commercially available natural muscovite block mica and is intended to be
independent of the basic color of the mica or its source.
1.2 Muscovite mica is characterized by having an optical axial angle between 50 and 75° (see Appendix X1); and has a weight
loss when heated for 5 min at 600°C not exceeding 0.2 % (based on the weight after drying at 120°C).
1.3 The visual system of classifying the quality of natural muscovite mica covered by this specification is based upon relative
amounts of visible foreign inclusions such as air bubbles, stains, and spots in combination with relative amounts and types of
waviness, as well as other physical properties. In this system, a perfectly clear, transparent, flat specimen of mica is the visual
standard of perfection. Increasing amounts of visual defects lower the visual quality, and a total of 13 levels of visual quality are
covered by this standard. This method of classification, generally known as the Bengal India System, is purely qualitative and is
entirely dependent on personal opinion and judgment.
1.4 The standards for visual quality classification that are covered in this classification are the best commercially available
concept of the various qualities and their relative positions. Variations in the methods of using and applying these standards from
those herein defined may be are specified by the purchaser, or defined by agreement between the supplier and the purchaser.
1.5 Standard size classifications are defined, based upon available usable rectangular areas and the minimum dimensions of the
rectangles that the pieces will yield. Precautions to be taken in making thickness measurements are also described.
1.6 This standard covers the following two definite forms of commercial preparation:
1.6.1 Form 1—Full-trimmed natural block mica, 0.007 in. 0.007 in. (0.178 mm) minimum thickness.
1.6.2 Form 2—Partially-trimmed natural block mica, 0.007 in. minimum thickness.
1.7 The basic color of mica, such as white, ruby, light green, dark green, brownish green, and rum, as well as other colors, and
the method of controlling the color and other problems associated with the basic color, are not a part of this classification.
1.8 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.9 Section 5 is technically identical to procedures specified in ISO 67-1981.
1.10 Section 6 differs somewhat in procedure from ISO 5972-1978, but data obtained by either should is expected to be
identical.
1.11 Section 7 is technically identical to procedures specified in ISO 2185-1972.
1.12 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
1
This classification is under the jurisdiction of ASTM Committee D09 on Electrical and Electronic Insulating Materials and is the direct responsibility of Subcommittee
D09.01 on Electrical Insulating Products.
Current edition approved Jan. 15, 2014Nov. 1, 2018. Published March 2014November 2018. Originally approved in 1932. Last previous edition approved in 20082014
ε1
as D351 – 97 (2008)D351 – 14. . DOI: 10.1520/D0351-14. 10.1520/D0351-18.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D351 − 18
2. Referenced Documents
2
2.1 ASTM Standards:
D374 Test Methods for Thickness of Solid Electrical Insulation (Metric) D0374_D0374M
D1711 Terminology Relating to Electrical Insulation
2.2 ISO Publications:
3
ISO 67-1981 Muscovite Mica Blocks, Thins, and Films—Grading by S
...
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