ASTM E438-92(2006)
(Specification)Standard Specification for Glasses in Laboratory Apparatus
Standard Specification for Glasses in Laboratory Apparatus
ABSTRACT
This specification covers the glasses commonly used to manufacture laboratory glass apparatus. Three types of glasses are included: Type I, Class A which is a low-expansion borosilicate glass, Type I, Class B which is an alumino-borosilicate glass, and Type II which is a soda-lime glass. Different tests shall be conducted in order to determine the following properties of glasses: linear coefficient of expansion, annealing point, softening point, density, and chemical durability.
SCOPE
1.1 This specification covers the glasses commonly used to manufacture laboratory glass apparatus.
General Information
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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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: E438 – 92 (Reapproved 2006)
Standard Specification for
Glasses in Laboratory Apparatus
This standard is issued under the fixed designation E438; 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.
TABLE 1 Chemical Requirements of Type I Glasses
1. Scope
Type I, Class A, Type I, Class B,
1.1 This specification covers the glasses commonly used to
weight % weight %
manufacture laboratory glass apparatus.
Major constituents, approximate:
SiO 81 73
2. Referenced Documents
B O 13 10
2 3
Al O 27
2.1 ASTM Standards: 2 3
BaO see below 0–2
C225 Test Methods for Resistance of Glass Containers to
CaO see below 1
Chemical Attack
NaO4 6
K O see below 1
C338 Test Method for Softening Point of Glass 2
Trace constituents, max:
C598 Test Method for Annealing Point and Strain Point of
As O plus Sb O 0.005 0.1
2 2 2 3
Glass by Beam Bending
PbO 0.1 0.1
MgO 0.1 0.3
C729 Test Method for Density of Glass by the Sink-Float
ZnO 0.1 0.1
Comparator
CaO 0.1 see above
A
E228 Test Method for Linear Thermal Expansion of Solid
K O 0.75 see above
All other constituents, max 0.2 1.0
Materials With a Push-Rod Dilatometer
A
Each manufacturer must publish the maximum percentage in his glass
3. Classification because certain limited applications require a level under 0.1 %.
3.1 Three types are included, as follows:
5. Physical Requirements
3.1.1 Type I, Class A—A low-expansion borosilicate glass.
3.1.2 Type I, Class B—An alumino-borosilicate glass.
5.1 The physical requirements for glasses shall be as pre-
3.1.3 Type II—A soda-lime glass. scribed in Table 3. The tolerances listed in Table 3 must be on
the published values of the manufacturer’s specific glass
4. Chemical Requirements
compositions.
4.1 The Type I, Class A and B glasses shall have the major
6. Keywords
constituents and comply with the restrictions on trace constitu-
ents given in Table 1. The major constituents will be varied to
6.1 glasses; laboratory
maintain the physical requirements as shown.
4.2 SuitableTypeIIglassesmayvarysomewhatinchemical
TABLE 2 Chemical Requirements of Type II Glasses
composition and still meet essential physical requirements.
Composition A, Composition B,
weight % weight %
Two such compositions are shown in Table 2; both are readily
available and are used for laboratory apparatus. Major constituents, approximate:
SiO 68 72
B O 2 .
2 3
Al O 32
2 3
This specification is under the jurisdiction of ASTM Committee E41 on
BaO 2 .
Laboratory Apparatus and is the direct responsibility of Subcommittee E41.01 on
CaO 5 5
App
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