ASTM C1503-01
(Specification)Standard Specification for Silvered Flat Glass Mirror
Standard Specification for Silvered Flat Glass Mirror
ABSTRACT
This specification covers the requirements for silvered flat glass mirrors of rectangular shape supplied as cut sizes, stock sheets or as lehr ends and to which no further processing (such as edgework or other fabrication) has been done. The quality requirements of silvered annealed monolithic clear and tinted flat glass mirrors up to a certain thickness are also discussed. The mirrors are intended to be used indoors for mirror glazing, for components of decorative accessories or for similar uses. The mirrors are not intended for use in environments where high humidity or airborne corrosion promoters, or both, are consistently present (such as swimming pool areas, ocean-going vessels, chemical laboratories and other corrosive environments). The classification of mirrors are according to the following properties: grades, cut size, stock sheet, lehr end, select quality, glazing quality, color (clear or tinted), and thickness. Different test methods shall be performed in order to determine or measure the following properties: reflectance, silver coating appearance, coating resistance, blemish (point and linear blemishes), dimension, and squareness.
SCOPE
1.1 This specification covers the requirements for silvered flat glass mirrors of rectangular shape supplied as cut sizes, stock sheets or as lehr ends and to which no further processing (such as edgework or other fabrication) has been done.
1.2 This specification covers the quality requirements of silvered annealed monolithic clear and tinted flat glass mirrors up to 6 mm (1/4 in.) thick. The mirrors are intended to be used indoors for mirror glazing, for components of decorative accessories or for similar uses.
1.3 This specification does not address safety glazing materials nor requirements for mirror applications. Consult model building codes and other applicable standards for safety glazing applications.
1.4 Mirrors covered in this specification are not intended for use in environments where high humidity or airborne corrosion promoters, or both, are consistently present (such as swimming pool areas, ocean-going vessels, chemical laboratories and other corrosive environments).
1.5 The dimensional values stated in metric units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.
1.6 The following safety hazards caveat pertains only to the test method portion Section 7 of this specification. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.
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Designation: C 1503 – 01
Standard Specification for
Silvered Flat Glass Mirror
This standard is issued under the fixed designation C 1503; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope E 903 Test Method for Solar Absorptance, Reflectance and
Transmittance of Materials Using Integrating Spheres
1.1 This specification covers the requirements for silvered
flat glass mirrors of rectangular shape supplied as cut sizes,
3. Terminology
stock sheets or as lehr ends and to which no further processing
3.1 Definitions—Refer to Terminology C 162 and the stan-
(such as edgework or other fabrication) has been done.
dards referenced in 2.2 as appropriate.
1.2 This specification covers the quality requirements of
3.1.1 blemishes—an imperfections in the body or on the
silvered annealed monolithic clear and tinted flat glass mirrors
surface of the mirror. For the purpose of this specification
up to 6 mm ( ⁄4 in.) thick. The mirrors are intended to be used
blemishes are divided into 2 categories:
indoors for mirror glazing, for components of decorative
3.1.1.1 point blemishes—knots, dirt, stones, gaseous inclu-
accessories or for similar uses.
sions (seeds and bubbles), tin particles, crush and other similar
1.3 This specification does not address safety glazing ma-
imperfections.
terials nor requirements for mirror applications. Consult model
3.1.1.2 linear blemishes—scratches, rubs, digs and other
building codes and other applicable standards for safety
similar imperfections.
glazing applications.
3.1.2 chip—an imperfection on the edge of a mirror lite due
1.4 Mirrors covered in this specification are not intended for
to breakage of a small fragment out of an otherwise regular
useinenvironmentswherehighhumidityorairbornecorrosion
surface.
promoters, or both, are consistently present (such as swimming
3.1.2.1 shell chip—a circular indentation in the mirror edge
pool areas, ocean-going vessels, chemical laboratories and
due to breakage of a small fragment.
other corrosive environments).
3.1.2.2 v-chip—a V-shaped chip indentation in the mirror
1.5 The dimensional values stated in metric units are to be
edge due to breakage of a small fragment.
regarded as the standard. The inch-pound units given in
3.1.2.3 chip width—the perpendicular distance from the
parentheses are for information only.
edge of the mirror to the inner edge of the chip.
1.6 The following safety hazards caveat pertains only to the
3.1.2.4 chip length—the distance, parallel to the edge of the
test method portion Section 7 of this specification. This
mirror, from one edge of a chip to the other.
standard does not purport to address all of the safety concerns,
3.1.2.5 chip depth—the measured distance of a chip from
if any, associated with its use. It is the responsibility of the user
the face of the mirror into the thickness.
of this standard to establish appropriate safety and health
3.1.3 clean cut edge—natural cut edge of mirror without
practices and determine the applicability of regulatory require-
further fabrication.
ments prior to use.
3.1.4 cluster—a group of not less than 3 point blemishes
2. Referenced Documents separated by not more than 50 mm (2 in.).
3.1.5 crush—a lightly pitted area in the glass surface
2.1 Reference to these documents shall be the latest issue
resulting in a dull gray or white appearance over the region.
unless otherwise specified by the authority applying this
3.1.6 dig—deep, short scratch in the glass surface.
specification:
3.1.7 dirt—a small particle of foreign material imbedded in
2.2 ASTM Standards:
the glass surface.
B 117 Practice for Operating Salt Spray (Fog) Apparatus
3.1.8 edge corrosion—change in the color or level of
C 162 Terminology of Glass & Glass Products
reflectance along the mirror edge as a result of degradation of
C 1036 Specification for Flat Glass
the silver coating from external sources.
3.1.9 edgework—fabrication of the mirror edge beyond the
This specification is under the jurisdiction of ASTM Committee C14 on Glass original clean-cut condition.
and Glass Products and is the direct responsibility of Subcommittee C14.08 on Flat
3.1.10 flare—a protrusion on the edge of a lite of mirror.
Glass.
Current edition approved June 10, 2001. Published August 2001.
Annual Book of ASTM Standards, Vol 03.02.
3 4
Annual Book of ASTM Standards, Vol 15.02. Annual Book of ASTM Standards, Vol 12.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C 1503
NOTE 1—Actual color or shade of tinted glass mirror may vary from
3.1.11 gaseous inclusion—(also known as seed or bubble)a
manufacturer to manufacturer and from batch to batch.
round or elongated bubble at the surface (open) or within the
body thickness leaving a cavity in the mirror.
4.4 Thickness—Mirrors are available in the following stan-
3.1.12 knot—an inhomogeneity in the form of a vitreous
dard nominal thicknesses:
lump in the mirror.
Thickness Intended use
3.1.13 mirror cut size—mirrors intended for final use in the
Desig- (Traditional Maximum Recommended
size ordered (i.e. mirrors not intended for recutting).
nation designation) recommended application
surface area per
3.1.14 mirror lehr end—mirrors intended for recutting by
cut size piece
the user into smaller sizes where it is expected that some
2.5 mm (single) Up to .5 sq. m. Utility mirrors where distortion
material may be lost in cutting due to blemishes and edge
(5 sq.ft.) and blemishes are not a
quality.
major concern
3.1.15 mirror stock sheet—mirrors intended for architec-
3.0 mm (double or Up to .75 sq. m. Mirror components and other
tural use and where trimming will be required. ⁄8 in.) (7.5 sq.ft.) general use applications
3.1.16 rub—an abrasion of the mirror surface producing a
4.0 mm ( ⁄32in.) Up to 1 sq. m. Mirror components and other
(10 sq.ft.) general use applications
frosted appearance.
3.1.17 scratch—damage on the glass surface in the form of
5.0 mm ( ⁄16in.) Up to 3 sq. m. Architectural use and other
(32 sq. ft.) applications where optical
a line caused by the relative movement of an object across and
quality is a major concern
in contact with the glass surface.
6.0 mm ( ⁄4 in.) Up to 3 sq. m. Architectural use and other
3.1.18 silver coating—the metallic silver coating in a sil-
(32 sq. ft.) applications where optical
vered mirror product.
quality is a major concern
3.1.19 silvered mirror—mirror product fabricated through
5. Ordering Information
the application of metallic silver and protected by a mirror
5.1 Purchasers should select the preferred options permitted
backing paint.
in this specification and include the following information in
3.1.20 spot silver fault—a small area at which the silver
procurement documents:
coating is partially or entirely absent.
5.1.1 Title, number, and date of this specification.
3.1.21 stone—a crystalline inclusion in the mirror.
5.1.2 Grade of mirror (see 4.1).
3.1.22 visible clouding—a frosted appearance in the re-
5.1.3 Quality of mirror (see 4.2).
flected image from a silvered mirror.
5.1.4 Color of mirror (see 4.3).
4. Classification and Intended Use
5.1.5 Thickness of mirror.
4.1 Grades—Mirrors furnished under this specification
5.1.6 Nominal length and width.
shall be of the following grades, as specified.
5.2 Packaging Requirements—Mirror packaging and pro-
4.1.1 Mirror Cut Size—Mirrors intended for final use in the
tection shall be standard manufacturer practice unless other-
size ordered (that is, mirrors not intended for recutting).
wise specified. Consult manufacturer before specifying.
4.1.2 Mirror Stock Sheet—Mirrors intended for architec-
6. Requirements
tural use and where trimming will be required.
4.1.3 Mirror Lehr End—Mirrors intended for recutting by 6.1 Reflectance Requirements—When measured in accor-
the user into smaller sizes where it is expected that some dance with Test Method 7.1, reflectance shall not be less than
material may be lost in cutting due to blemishes and edge the following:
quality. 6.1.1 For clear glass mirrors—minimum visible light re-
4.2 Qualities—Mirrors furnished under this specification flected = 83 %.
shall be of the following qualities, as specified. 6.1.2 For tinted glass mirrors—minimum visible light
4.2.1 Mirror Select Quality—(Usually available in 6 mm reflected = (T) (where T = the visible light transmission value
( ⁄4 in.) clear mirror only.) Recommended or intended or both, for the glass substrate in its unsilvered state.)
for use in visually demanding applications requiring minimal 6.2 Coating Requirements:
distortion and blemishes. 6.2.1 Appearance of Silver Coating—When inspected in
4.2.2 Mirror Glazing Quality—Recommended or intended
accordance with Test Method 7.2, the silver coating shall be
or both, for general use where limited levels of minor blem- free of visible blemishes.
ishes or distortion, or both are acceptable. 6.2.2 Coating Resistance Requirements—When tested in
4.3 Color—The glass substrate may be clear or tinted. accordance with Test Method 7.3 mirrors shall meet the
4.3.1 Clear Glass Mirrors—Mirrors made with clear requirements shown in Table 6.
(untinted) glass. 6.3 Blemish Limits—Blemishes, other than visible blem-
4.3.2 Tinted Glass Mirrors—Mirrors made with tinted (col- ishes in the silver coating, are permitted within the following
ored) glass. Intended for use primarily in decorative applica- limits.
tions where diminished light reflectance is not a concern. A 6.3.1 Blemish Limits for Mirror Cut Size and Mirror Stock
variety of tinted glass substrates are available. The specific tint Sheet Grades:
desired should be specified by the purchaser and is subject to 6.3.1.1 Point Blemish Limits—When inspected in accor-
availability. Not all grades or qualities may be available in dance with Test Method 7.4.1 point blemishes shall be within
tinted glass mirror. the limits shown in Table 2.
C 1503
TABLE 1 Dimensional Tolerances for Mirror Cut Size, Mirror Stock Sheet and Mirror Lehr End Grades
A B
Thickness Designation Thickness Range Squareness Length and Width Tolerance
Metric (Traditional) Cut Size Stock Sheet &
Lehr End
mm (inches) Max. D1-D2 6 mm 6 mm
min max min max mm (inches) (6 in.) (6 in.)
5 1 1
2.5 mm (Single) 2.16 to 2.57 (0.085 to 0.101) 2.0 ( ⁄64) 1.6 ( ⁄16) 6.4 ( ⁄4)
1 5 1 1
3.0 mm (Double- ⁄8 in.) 2.92 to 3.40 (0.115 to 0.134) 2.0 ( ⁄64) 1.6 ( ⁄16) 6.4 ( ⁄4)
5 5 1 1
4.0 mm ( ⁄32 in.) 3.78 to 4.19 (0.149 to 0.165) 2.0 ( ⁄64) 1.6 ( ⁄16) 6.4 ( ⁄4)
3 5 1 1
5.0 mm ( ⁄16 in.) 4.57 to 5.07 (0.180 to 0.199) 2.0( ⁄64) 1.6 ( ⁄16) 6.4 ( ⁄4)
1 5 1 1
6.0 mm ( ⁄4 in.) 5.56 to 6.20 (0.219 to 0.244) 2.0 ( ⁄64) 1.6 ( ⁄16) 6.4 ( ⁄4)
A
The mirror shall not vary in thickness more than 0.1 mm (.004 in.) over a 100 mm (4 in.) area.
B
Length and width of mirrors include flares and bevels.
TABLE 2 Allowable Point Blemish Size and Distribution for Mirror Cut Size and Mirror Stock Sheet Grades of Mirrors
A B
Blemish Size Mirror Cut Size Mirror Stock Sheet
Mirror Select Quality Mirror Glazing Quality Mirror Select Quality Mirror Glazing Quality
(usually available in 6 mm ( ⁄4 in.) (usually available in 6
clear mirror only) mm ( ⁄4 in.)
clear mirror only)
C C C C
Central Outer Central Outer
D D D D
<0.30mm Allowed with a Allowed with a Allowed Allowed Allowed Allowed
(<.012 in.) minimum separation minimum separation
of 300 mm (12 in.) of 300 mm (12 in.)
D
$0.30 mm Allowed with a Allowed with a Allowed with a Allowed with a Allowed with a Allowed
<0.50 mm minimum separation minimum separation minimum separation minimum separation minimum separation
($.012 in. <0.02 in.) of 600 mm (24 in.) of 300 mm (12 in.) of 300 mm (12 in.) of 300 mm (12 in.) of 1200 mm (48 in.)
$0.50mm None Allowed Allowed with a None Allowed Allowed with a None Allowed Allowed with a
<0.80 mm minimum separation minimum separation minimum separation
($.02 in. <0.032 in.) of 900 mm (36 in.) of 300 mm (12 in.) of 600 mm (24 in.)
$0.80 mm None Allowed None Allowed None Allowed Allowed with a None Allowed Allowed with a
<1.20 mm minimum minimum separation
($.032 in. <0.047 in.) separation of 1500 mm of 1200 mm (48 in.)
(60 in.)
$1.20 mm None Allowed None Allowed None Allowed None Allowed None Allowed Allowed with a
<1.50 mm minimum separation
($.047 in. <0.059 in.) of 1500 mm (60 in.)
$1.50 mm None Allowed None Allowed None Allowed None Allowed None Allowed None Allowed
($.059 in.)
A
See 7.4.1 for detection, 7.4.1.1 for measurement and 7.4.3 for distribution of point blemishes.
B
See 4.4 for maximum recommended surface area per cut size piece.
C
The central area is considered to form a square or rectangle defined by the center 80 % of the length and 80 % of the width dimensions centered on a lite of mirror.
The remaining area is considered the outer area.
D
Provided that clusters are not formed.
TABLE 3 Allowable Point Blemish Size and Distribution For
6.3.2.2 Linear Blemish Limits—When tested in accordance
Mirror Lehr End Grade
with Test Method 7.4.2 mirrors shall meet the quality require-
NOTE—Follow the requirements for the appropriate Quality (Mirror ments shown in Table 4.
Select Quality or Mirror Glazing Quality) for Mirror Stock Sheet in Table
6.4 Edge Quality Requirements—Edges shall be clean cut.
2 with the following additional details for Mirror Lehr End Requirements:
(Types and qualities of edgework are not within the scope of
If mirror area <7 m (75 SF)—one rejectable defect allowed
this specification. Consult manufacturer before specifying.)
If mirror area$7m (75 SF)—two rejectable defects allowed
6.4.1 Shell Chips—Shell chips are permitted in the edges of
clean cut mirror as long as they do not exceed the acceptance
criteria shown in Table 5.
6.4.2 V-Chips—V-Chips are not permitted.
6.3.1.2 Linear Blemish Limits—When inspected in accor-
6.5 Dimensional Tolerances:
dance with Test Method 7.4.2 linear blemishes shall be within
6.5.1 Thickness—When measured at any point throughout
the limits shown in Table 4.
the sheet, tolerances for thickness (including uniformity of
6.3.2 Blemish Limits for Mirror Lehr End Grade:
thickness) of mirrors shall be in accordance with Table 1.
6.3.2.1 Point Blemish Limits—When tested in accordance 6.5.2 Length and Width—When measured in accordance
with Test Method 7.4.1 mirrors shall meet the quality require- with Test Method 7.5, tolerances for length and width of
ments shown in Tables 2 and 3. mirrors shall be in accordance with Table 1.
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