ASTM E438-92(R2018) pdf free download
ASTM E438-92(R2018) pdf free download.Standard Specification for Glasses in Laboratory Apparatus
1. Scope
1.1 This specification covers the glasses commonly used to manufacture laboratory glass apparatus. 1.2 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards: 2 C225 Test Methods for Resistance of Glass Containers to Chemical Attack C338 Test Method for Softening Point of Glass C598 Test Method for Annealing Point and Strain Point of Glass by Beam Bending C729 Test Method for Density of Glass by the Sink-Float Comparator E228 Test Method for Linear Thermal Expansion of Solid Materials With a Push-Rod Dilatometer
3. Classification
3.1 Three types are included, as follows: 3.1.1 Type I, Class A—A low-expansion borosilicate glass. 3.1.2 Type I, Class B—An alumino-borosilicate glass. 3.1.3 Type II—A soda-lime glass.
4. Chemical Requirements
4.1 The Type I, Class A and B glasses shall have the major constituents and comply with the restrictions on trace constitu- ents given in Table 1. The major constituents will be varied to maintain the physical requirements as shown. 4.2 Suitable Type II glasses may vary somewhat in chemical composition and still meet essential physical requirements. Two such compositions are shown in Table 2; both are readily available and are used for laboratory apparatus.
5. Physical Requirements
5.1 The physical requirements for glasses shall be as pre- scribed in Table 3. The tolerances listed in Table 3 must be on the published values of the manufacturer’s specific glass compositions.
6. Keywords
6.1 glasses; laboratory
