ASTM C336-71(2020)
(Test Method)Standard Test Method for Annealing Point and Strain Point of Glass by Fiber Elongation
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.
General Information
Relations
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: C336 − 71 (Reapproved 2020)
Standard Test Method for
Annealing Point and Strain Point of Glass by Fiber
1
Elongation
This standard is issued under the fixed designation C336; 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 3. Terminology
3.1 Definitions:
1.1 This test method covers the determination of the anneal-
3.1.1 annealing point, n—that temperature at which internal
ing point and the strain point of a glass by measuring the
stresses in a glass are substantially relieved in a matter of
viscous elongation rate of a fiber of the glass under prescribed
4,5,6
condition. minutes. During a test in accordance with the requirements
of this method, the viscous elongation rate is measured by a
1.2 The annealing and strain points shall be obtained by
suitable extensometer while the specimen fiber is cooling at a
following the specified procedure after calibration of the
rateof4 61°C/min.Theelongationrateattheannealingpoint
apparatus using fibers of standard glasses having known
is approximately 0.14 mm/min for a fiber of 0.65 mm diam-
annealing and strain points, such as those specified and
6
eter.
certified by the National Institute of Standards and Technology
2
3.1.2 annealing range, n—the range of glass temperature in
(NIST) (see Appendix X1).
which stresses in glass articles can be relieved at a commer-
1.3 This standard does not purport to address all of the
cially desirable rate. For purposes of comparing glasses, the
safety concerns, if any, associated with its use. It is the
annealing range is assumed to correspond with the tempera-
responsibility of the user of this standard to establish appro-
tures between the annealing point (AP) and the strain point
priate safety, health, and environmental practices and deter-
(StP).
mine the applicability of regulatory limitations prior to use.
3.1.3 strain point, n—that temperature at which the internal
1.4 This international standard was developed in accor-
stresses in a glass are substantially relieved in a matter of
dance with internationally recognized principles on standard-
hours. The strain point is determined by extrapolation of the
ization established in the Decision on Principles for the
annealing point data and is the temperature at which the
Development of International Standards, Guides and Recom-
viscous elongation rate is 0.0316 times that observed at the
mendations issued by the World Trade Organization Technical
annealing point.
Barriers to Trade (TBT) Committee.
4. Significance and Use
2. Referenced Documents
3 4.1 This test method provides data useful for (1) estimating
2.1 ASTM Standards:
stress release, (2) the development of proper annealing
C338 Test Method for Softening Point of Glass
schedules, and (3) estimating setting points for seals.
C598 Test Method for Annealing Point and Strain Point of
Accordingly, its usage is widespread throughout
Glass by Beam Bending
manufacturing, research, and development. It can be utilized
for specification acceptance.
1
This test method is under the jurisdiction of ASTM Committee C14 on Glass
and Glass Products and is the direct responsibility of Subcommittee C14.04 on
4
Physical and Mechanical Properties. Littleton, J. T., and Roberts, E. H., “A Method for Determining the Annealing
Current edition approved Aug. 1, 2020. Published August 2020. Originally Temperature of Glass,” Journal of the Optical Society of America, Vol 4, 1920, p.
approved in 1954. Last previous edition approved in 2015 as C336 – 71 (2015). 224.
5
DOI: 10.1520/C0336-71R20. Lillie, H. R., “Viscosity of Glass Between the Strain Point and Melting
2
Available from National Institute of Standards and Technology (NIST), 100 Temperature,” Journal of American Ceramic Society, Vol 14, 1931, p. 502;
Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov. “Re-Evaluation of Glass Viscosities at Annealing and Strain Points,” Journal of
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or American Ceramic Society, Vol 37, 1954, p. 111.
6
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM McGraw, D. A. and Babcock, C. L., “Effect of Viscosity and Stress Level on
Standards volume information, refer to the standard’s Document Summary page on Rate of Stress Release in Soda-Lime, Potash-Barium and Borosilicate Glasses,”
the ASTM web
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