iTeh StandardsiTeh Standards
EURUSD
Your shopping cart is empty.
ASTM

ASTM C338-93(2008)

(Test Method)

Standard Test Method for Softening Point of Glass

Standard Test Method for Softening Point of Glass

SIGNIFICANCE AND USE
This test method is useful to determine approximately the temperature below which the glass behaves as a rigid solid in glass-forming operations and for a control test to indicate changes in composition. It has been found useful for specification acceptance and for providing information in research and development work with glass.
SCOPE
1.1 This test method covers the determination of the softening point of a glass by determining the temperature at which a round fiber of the glass, nominally 0.65 mm in diameter and 235 mm long with specified tolerances, elongates under its own weight at a rate of 1 mm/min when the upper 100 mm of its length is heated in a specified furnace at the rate of 5 ± 1°C/min.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 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 limitations prior to use.

General Information

Status
Historical
Publication Date
31-Mar-2008
ICS
81.040.10 - Raw materials and raw glass
Technical Committee
C14 - Glass and Glass Products
Drafting Committee
C14.04 - Physical and Mechanical Properties
Current Stage
Ref Project

Relations

Replaces
ASTM C338-93(2003) - Standard Test Method for Softening Point of Glass
Effective Date
01-Apr-2008
Replaced By
ASTM C338-93(2013) - Standard Test Method for Softening Point of Glass
Effective Date
01-Oct-2013
Referred By
ASTM F79-69(2019) - Standard Specification for Type 101 Sealing Glass
Effective Date
01-Apr-2008
Referred By
ASTM E438-92(2018) - Standard Specification for Glasses in Laboratory Apparatus
Effective Date
01-Apr-2008
Referred By
ASTM C336-71(2020) - Standard Test Method for Annealing Point and Strain Point of Glass by Fiber Elongation
Effective Date
01-Apr-2008
Referred By
ASTM C162-05(2015) - Standard Terminology of<brk type="line"/> Glass and Glass Products
Effective Date
01-Apr-2008
Referred By
ASTM F105-72(2019) - Standard Specification for Type 58 Borosilicate Sealing Glass
Effective Date
01-Apr-2008
Referred By
ASTM C1351M-96(2022) - Standard Test Method for Measurement of Viscosity of Glass Between 10<sup>4</sup> Pa·s and 10<sup>8</sup> Pa·s by Viscous Compression of a Solid Right Cylinder [Metric]
Effective Date
01-Apr-2008
Referred By
ASTM C1350M-96(2019) - Standard Test Method for Measurement of Viscosity of Glass Between Softening Point and Annealing Range (Approximately 10<sup>8</sup> Pa&#xb7;s to Approximately 10<sup>13</sup> Pa&#xb7;s) by Beam Bending (Metric)
Effective Date
01-Apr-2008

Buy Standard

ASTM C338-93(2008) - Standard Test Method for Softening Point of GlassASTM C338-93(2008) - Standard Test Method for Softening Point of Glass
PreviousNext
Standard
ASTM C338-93(2008) - Standard Test Method for Softening Point of Glass
English language
3 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (Sample)


NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C338 − 93(Reapproved 2008)
Standard Test Method for
Softening Point of Glass
This standard is issued under the fixed designation C338; 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 Department of Defense.
1. Scope 3.1.2 Furnace Stand—A means shall be provided for sup-
porting the furnace so that the fiber hangs below it. This stand
1.1 This test method covers the determination of the soft-
must be provided with a leveling device such as three screws.
ening point of a glass by determining the temperature at which
The stand shown in Fig. 1 is convenient when used with either
a round fiber of the glass, nominally 0.65 mm in diameter and
a cathetometer or a telescope and scale.
235mmlongwithspecifiedtolerances,elongatesunderitsown
3.1.3 Heating Rate Controller—Suitable controls shall be
weight at a rate of 1 mm/min when the upper 100 mm of its
provided for maintaining the furnace heating rate at 5 6
length is heated in a specified furnace at the rate of 5 6
1°C/min.
1°C/min.
1.2 The values stated in SI units are to be regarded as
NOTE 1—A continually adjustable transformer has proved effective for
standard. No other units of measurement are included in this controlling the heating rate.
standard.
3.1.4 Temperature-Measuring Equipment—The furnace
1.3 This standard does not purport to address all of the
temperature shall be measured with a calibrated Type R or S
safety concerns, if any, associated with its use. It is the
thermocouple and a calibrated potentiometer capable of mea-
responsibility of the user of this standard to establish appro-
suring the true temperature of the furnace within 60.2°C. The
priate safety and health practices and determine the applica-
cold junction shall be maintained at 0°C by means of an ice
bility of regulatory limitations prior to use.
bath.An alternative acceptable means of temperature measure-
ment is the use of a potentiometer to oppose the thermocouple
2. Significance and Use
electromotive force. This potentiometer shall be set at a
standard setting for the type of glass being measured, and
2.1 This test method is useful to determine approximately
galvanometer deflection shall serve as a means of obtaining
the temperature below which the glass behaves as a rigid solid
relative temperatures, the deflection of the galvanometer hav-
in glass-forming operations and for a control test to indicate
ing been calibrated. Also acceptable for temperature measure-
changes in composition. It has been found useful for specifi-
ment is a solid-state digital thermometer that is capable of the
cation acceptance and for providing information in research
accuracy specified.
and development work with glass.
3.1.5 Fiber-Elongation Measurement Equipment—The fiber
3. Apparatus elongation shall be measured by a device capable of measuring
the position of the end of the fiber within 0.02 mm throughout
3.1 The apparatus for determining the softening point of
the entire elongation period.
glass shall consist essentially of an electrically heated resis-
tance furnace, a furnace stand, a device for controlling the
NOTE 2—Suitable devices that have proved effective for measuring the
heating rate of the furnace, equipment for measuring the
elongation are cathetometers, projection magnifiers, and telescope and
scale combinations.
temperature of the furnace, and equipment for measuring the
elongation rate of a fiber of glass suspended in the furnace.
3.1.6 Timer—A timing device with a least count and accu-
3.1.1 Furnace—The furnace shall conform in all essential
racy of 1 s shall be used.
respects to the requirements shown in Fig. 1.
4. Preparation of Test Specimens
4.1 The fiber specimen used for the test shall meet the
This test method is under the jurisdiction of ASTM Committee C14 on Glass
following requirements:
and Glass Products and is the direct responsibility of Subcommittee C14.04 on
Physical and Mechanical Properties.
4.1.1 It shall be round.
Current edition approved April 1, 2008. Published June 2008. Originally
4.1.2 It shall be smooth and shall contain no void spots or
approved in 1954. Last previous edition approved in 2003 as C338 – 93 (2003).
DOI: 10.1520/C0338-93R08. foreign matter.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C338 − 93 (2008)
FIG. 1 Details of Softening Point Furnace
C338 − 93 (2008)
4.1.3 Its average diameter shall be 0.65 6 0.10 mm and the 6.2 Again, cool and hold the furnace about 20°C below the
maximum diameter shall not exceed the minimum diameter by expected softening point and insert the fiber in the furnace by
more than 0.02 mm over the entire length of the fiber. placing the bead end in the furnace sample holder. Check the
4.1.4 It shall be 235 6 1 mm in length, not including the top fiber to be certain it is hanging free in the center of the furnace
bead. Test fibers conforming to these requirements may be and relevel the furnace if necessary. Standardize the potenti-
drawn by attaching a clean sample of the glass under test ometer
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.

This May Also Interest You

ASTM
ASTM C158-23(Test Method)
Standard Test Methods for Strength of Glass by Flexure (Determination of Modulus of Rupture)

SIGNIFICANCE AND USE
4.1 For the purpose of this test, glasses and glass-ceramics are considered brittle (perfectly elastic) and to have the property that fracture normally occurs at the surface of the test specimen from the principal tensile stress. The flexural strength is considered a valid measure of the tensile strength subject to the considerations that follow.  
4.2 The flexural strength for a group of test specimens is influenced by variables associated with the test procedure. Such factors are specified in the test procedure or required to be stated in the report. These include but are not limited to the rate of stressing, the test environment, and the area of the specimen subjected to stress.  
4.2.1 In addition, the variables having the greatest effect on the flexural strength value for a group of test specimens are the condition of the surfaces and glass quality near the surfaces in regard to the number and severity of stress-concentrating discontinuities or flaws, and the degree of prestress existing in the specimens. Each of these can represent an inherent part of the strength characteristic being determined or can be a random interfering factor in the measurement.  
4.2.2 Test Method A is designed to include the condition of the surface of the specimen as a factor in the measured strength. Therefore, subjecting a fixed and significant area of the surface to the maximum tensile stress is desirable. Since the number and severity of surface flaws in glass are primarily determined by manufacturing and handling processes, this test method is limited to products from which specimens of suitable size can be obtained with minimal dependence of measured strength upon specimen preparation techniques. This test method is therefore designated as a test for flexural strength of flat glass.  
4.2.3 Test Method B describes a general procedure for test, applicable to specimens of rectangular or elliptical cross section. This test method is based on the assumption that a comparative ...
SCOPE
1.1 These test methods cover the determination of the flexural strength (the modulus of rupture in bending) of glass and glass-ceramics.  
1.2 These test methods are applicable to annealed and prestressed glasses and glass-ceramics available in varied forms. Alternative test methods are described; the test method used shall be determined by the purpose of the test and geometric characteristics of specimens representative of the material.  
1.2.1 Test Method A is a test for flexural strength of flat glass.  
1.2.2 Test Method B is a comparative test for flexural strength of glass and glass-ceramics.  
1.3 The test methods appear in the following order:    
Sections  
Test Method A  
7 to 10  
Test Method B  
11 to 16  
1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 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.

  • Standard
    10 pages
    English language
    sale 15% off
  • Standard
    10 pages
    English language
    sale 15% off
ASTM
ASTM C965-23(Practice)
Standard Practice for Measuring Viscosity of Glass Above the Softening Point

SIGNIFICANCE AND USE
3.1 This practice is useful in determining the viscosity-temperature relationships for glasses and corresponding useful working ranges. See Terminology C162.
SCOPE
1.1 This practice covers the determination of the viscosity of glass above the softening point through the use of a platinum alloy spindle immersed in a crucible of molten glass. Spindle torque, developed by differential angular velocity between crucible and spindle, is measured and used to calculate viscosity. Generally, data are taken as a function of temperature to describe the viscosity curve for the glass, usually in the range from 1 to 106 Pa·s.  
1.2 Two procedures with comparable precision and accuracy are described and differ in the manner for developing spindle torque. Procedure A employs a stationary crucible and a rotated spindle. Procedure B uses a rotating crucible in combination with a fixed spindle.  
1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

  • Standard
    4 pages
    English language
    sale 15% off
  • Standard
    4 pages
    English language
    sale 15% off
ASTM
ASTM C169-16(2022)(Test Method)
Standard Test Methods for Chemical Analysis of Soda-Lime and Borosilicate Glass

SIGNIFICANCE AND USE
3.1 These test methods can be used to ensure that the chemical composition of the glass meets the compositional specification required for the finished glass product.  
3.2 These test methods do not preclude the use of other methods that yield results within permissible variations. In any case, the analyst should verify the procedure and technique employed by means of a National Institute of Standards and Technology (NIST) standard reference material having a component comparable with that of the material under test. A list of standard reference materials is given in the NIST Special Publication 260,3 current edition.  
3.3 Typical examples of products manufactured using soda-lime silicate glass are containers, tableware, and flat glass.  
3.4 Typical examples of products manufactured using borosilicate glass are bakeware, labware, and fiberglass.  
3.5 Typical examples of products manufactured using fluoride opal glass are containers, tableware, and decorative glassware.
SCOPE
1.1 These test methods cover the quantitative chemical analysis of soda-lime and borosilicate glass compositions for both referee and routine analysis. This would be for the usual constituents present in glasses of the following types: (1) soda-lime silicate glass, (2) soda-lime fluoride opal glass, and (3) borosilicate glass. The following common oxides, when present in concentrations greater than indicated, are known to interfere with some of the determinations in this method: 2 % barium oxide (BaO), 0.2 % phosphorous pentoxide (P2O5), 0.05 % zinc oxide (ZnO), 0.05 % antimony oxide (Sb2O3), 0.05 % lead oxide (PbO).  
1.2 The analytical procedures, divided into two general groups, those for referee analysis, and those for routine analysis, appear in the following order:    
Sections  
Procedures for Referee Analysis:  
Silica  
10  
BaO, R2O2 (Al2O3 + P2O5), CaO, and MgO  
11 – 15  
Fe2O3, TiO2, ZrO2 by Photometry and Al2O3 by Com-
plexiometric Titration  
16 – 22  
Cr2O3 by Volumetric and Photometric Methods  
23 – 25  
MnO by the Periodate Oxidation Method  
26 – 29  
Na2O by the Zinc Uranyl Acetate Method and K2O by
the Tetraphenylborate Method  
30 – 33  
SO3 (Total Sulfur)  
34 – 35  
As2O3 by Volumetric Method  
36 – 40  
Procedures for Routine Analysis:  
Silica by the Single Dehydration Method  
42 – 44  
Al2O3, CaO, and MgO by Complexiometric Titration,
and BaO, Na2O, and K2O by Gravimetric Method  
45 – 51  
BaO, Al2O3, CaO, and MgO by Atomic Absorption; and
Na2O and K2O by Flame Emission Spectroscopy  
52 – 59  
SO3 (Total Sulfur)  
60  
B2O3  
61 – 62  
Fluorine by Pyrohydrolysis Separation and Specific Ion
Electrode Measurement  
63 – 66  
P2O5 by the Molybdo-Vanadate Method  
67 – 70  
Colorimetric Determination of Ferrous Iron Using 1,10
Phenanthroline  
71 – 76  
1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

  • Standard
    24 pages
    English language
    sale 15% off
ASTM
ASTM C729-11(2022)(Test Method)
Standard Test Method for Density of Glass by the Sink-Float Comparator

SIGNIFICANCE AND USE
4.1 The sink-float comparator method of test for glass density provides the most accurate (yet convenient for practical applications) method of evaluating the density of small pieces or specimens of glass. The data obtained are useful for daily quality control of production, acceptance or rejection under specifications, and for special purposes in research and development.  
4.2 Although this test scope is limited to a density range from 1.1 g/cm3 to 3.3 g/cm3, it may be extended (in principle) to higher densities by the use of other miscible liquids (Test Method F77) such as water and thallium malonate-formate (approximately 5.0 g/cm3). The stability of the liquid and the precision of the test may be reduced somewhat, however, at higher densities.
SCOPE
1.1 This test method covers the determination of the density of glass or nonporous solids of density from 1.1 g/cm 3 to 3.3 g/cm 3. It can be used to determine the apparent density of ceramics or solids, preferably of known porosity.  
1.2 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.3 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.

  • Standard
    6 pages
    English language
    sale 15% off
ASTM
ASTM C829-81(2022)(Practice)
Standard Practices for Measurement of Liquidus Temperature of Glass by the Gradient Furnace Method

SIGNIFICANCE AND USE
3.1 These practices are useful for determining the maximum temperature at which crystallization will form in a glass, and a minimum temperature at which a glass can be held, for extended periods of time, without crystal formation and growth.
SCOPE
1.1 These practices cover procedures for determining the liquidus temperature (Note 1) of a glass (Note 1) by establishing the boundary temperature for the first crystalline compound, when the glass specimen is held at a specified temperature gradient over its entire length for a period of time necessary to obtain thermal equilibrium between the crystalline and glassy phases.  
Note 1: These terms are defined in Terminology C162.  
1.2 Two methods are included, differing in the type of sample, apparatus, procedure for positioning the sample, and measurement of temperature gradient in the furnace. Both methods have comparable precision. Method B is preferred for very fluid glasses because it minimizes thermal and mechanical mixing effects.  
1.2.1 Method A employs a trough-type platinum container (tray) in which finely screened glass particles are fused into a thin lath configuration defined by the trough.  
1.2.2 Method B employs a perforated platinum tray on which larger screened particles are positioned one per hole on the plate and are therefore melted separately from each other.2  
1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

  • Standard
    9 pages
    English language
    sale 15% off
ASTM
ASTM C429-21(Test Method)
Standard Test Method for Sieve Analysis of Raw Materials for Glass Manufacture

SIGNIFICANCE AND USE
4.1 The purpose of this test method is to determine the particle size distribution of the glass raw materials.
SCOPE
1.1 This test method covers the sieve analysis of common raw materials for glass manufacture, such as sand, soda-ash, limestone, alkali-alumina silicates, and other granular materials used in glass batch.  
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

  • Standard
    8 pages
    English language
    sale 15% off
  • Standard
    8 pages
    English language
    sale 15% off
ASTM
ASTM C146-21(Test Method)
Standard Test Methods for Chemical Analysis of Glass Sand

SIGNIFICANCE AND USE
3.1 These test methods can be used to ensure that the chemical composition of the glass sand meets the compositional specification required for this raw material.  
3.2 These test methods do not preclude the use of other methods that yield results within permissible variations. In any case, the analyst should verify the procedure and technique used by means of a National Institute of Standards and Technology (NIST) standard reference material or other similar material of known composition having a component comparable with that of the material under test. A list of standard reference materials is given in the NIST Special Publication 260, current edition.
SCOPE
1.1 These test methods cover the chemical analysis of glass sands. They are useful for either high-silica sands (99 % + silica (SiO2)) or for high-alumina sands containing as much as 12 to 13 % alumina (Al2O3). Generally nonclassical, these test methods are rapid and accurate. They include the determination of silica and of total R2O3 (see 11.2.4), and the separate determination of total iron as iron oxide (Fe2O3), titania (TiO2), chromium oxide (Cr2O3), zirconia (ZrO2), and ignition loss. Included are procedures for the alkaline earths and alkalies. High-alumina sands may contain as much as 5 to 6 % total alkalies and alkaline earths. It is recommended that the alkalies be determined by flame photometry and the alkaline earths by absorption spectrophotometry.  
1.2 These test methods, if followed in detail, will provide interlaboratory agreement of results.  
Note 1: For additional information, see Test Methods C169 and Practices E50.  
1.3 These test methods appear in the following order:    
Procedures for Referee Analysis:  
Section  
Silica (SiO2)—Double Dehydration  
10  
Total R2O3—Gravimetric  
11  
Fe2O3, TiO2, ZrO2, Cr2O3, by Photometric Methods and
Al2O3 by Complexiometric Titration  
12 – 17  
Preparation of the Sample for Determination of Iron
Oxide, Titania, Alumina, and Zirconia  
12  
Iron Oxide (as Fe2O3) by 1,10-Phenanthroline Method  
13  
Titania (TiO2) by the Tiron Method  
14  
Alumina (Al2O3) by the CDTA Titration Method  
15  
Zirconia (ZrO2) by the Pyrocatechol Violet Method  
16  
Chromium Oxide (Cr2O3) by the 1,5-Diphenylcarbo-
hydrazide Method  
17  
Procedures for Routine Analysis:  
Silica (SiO2)—Single Dehydration  
19  
Al2O3, CaO, and MgO—Atomic Absorption Spec-
trophotometry  
20–25  
Na2O and K2O—Flame Emission Spectrophotometry  
26-27  
Loss on Ignition (LOI)  
28  
1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 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.

  • Standard
    12 pages
    English language
    sale 15% off
  • Standard
    12 pages
    English language
    sale 15% off
ASTM
ASTM C730-98(2021)(Test Method)
Standard Test Method for Knoop Indentation Hardness of Glass

SIGNIFICANCE AND USE
4.1 The Knoop indentation hardness is one of many properties that is used to characterize glasses. Attempts have been made to relate Knoop indentation hardness to tensile strength, grinding speeds, and other hardness scales, but no generally accepted methods are available. Such conversions are limited in scope and should be used with caution, except for special cases where a reliable basis for the conversion has been obtained by comparison tests.
SCOPE
1.1 This test method covers the determination of the Knoop indentation hardness of glass and the verification of Knoop indentation hardness testing machines using standard glasses.  
1.2 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.3 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.

  • Standard
    5 pages
    English language
    sale 15% off
ASTM
ASTM C770-16(2020)(Test Method)
Standard Test Method for Measurement of Glass Stress—Optical Coefficient

SIGNIFICANCE AND USE
3.1 Stress-optical coefficients are used in the determination of stress in glass. They are particularly useful in determining the magnitude of thermal residual stresses for annealing or pre-stressing (tempering) glass. As such, they can be important in specification acceptance.
SCOPE
1.1 This test method covers procedures for determining the stress-optical coefficient of glass, which is used in photoelastic analyses. In Procedure A the optical retardation is determined for a glass fiber subjected to uniaxial tension. In Procedure B the optical retardation is determined for a beam of glass of rectangular cross section when subjected to four-point bending. In Procedure C, the optical retardation is measured for a beam of glass of rectangular cross-section when subjected to uniaxial compression.  
1.2 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.3 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.

  • Standard
    9 pages
    English language
    sale 15% off
ASTM
ASTM C336-71(2020)(Test Method)
Standard Test Method for Annealing Point and Strain Point of Glass by Fiber Elongation

SIGNIFICANCE AND USE
4.1 This test method provides data useful for (1) estimating stress release, (2) the development of proper annealing schedules, and (3) estimating setting points for seals. Accordingly, its usage is widespread throughout manufacturing, research, and development. It can be utilized for specification acceptance.
SCOPE
1.1 This test method covers the determination of the annealing point and the strain point of a glass by measuring the viscous elongation rate of a fiber of the glass under prescribed condition.  
1.2 The annealing and strain points shall be obtained by following the specified procedure after calibration of the apparatus using fibers of standard glasses having known annealing and strain points, such as those specified and certified by the National Institute of Standards and Technology (NIST)2 (see Appendix X1).  
1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

  • Standard
    5 pages
    English language
    sale 15% off