Borosilicate
Pyrex® Brand Labware
Of the hundreds of commercial glasses produced, Code No. 7740 borosilicate glass comes closest to being the ideal glass for most laboratory applications.
With proper care, it will withstand nearly all temperatures used in normal laboratory use. It is highly resistant to chemical attack. Its low coefficient of expansion allows it to be manufactured with heavy walls, giving it mechanical strength, while retaining reasonable heat resistance. And, it is a glass that can be fabricated more easily than most other glasses, thus making it more economical.
7740
Corning Trademark: PYREX®
Common Names
Borosilicate -- Low Expansion -- Type 1 Glass
Standards
Type 1, Class A Borosilicate conforming to federal specification DD-G-54 lb and ASTM E-438. Also meets the U.S. Pharmacopoeia specs for Type 1 Borosilicate Glass.
Applications
Designed for use in all products requiring very high resistance to strong acids, alkalis and products intended for use in heat applications such as autoclaves, hot plates, and open flame.
Products
Beakers, burets, bottles, centrifuge tubes, condensers, cylinders, desiccators, dishes, flasks, fritted ware, funnels, ground joints, jars stopcocks, tubing and other assorted products.
Warnings
Thick-walled ware, such as bottles, jars and desiccators, should not be heated over a flame, a hot plate, or other comparable source of heat.
Do not use hydrofluoric or hot phosphoric acid in glass.
Do not use scratched or abraded glassware.
Hot alkalis will etch glass.
Composition | (percent approx.) |
SiO2 B2O3 Na2O Al2O3 Na2O |
80.6% 13.0% 4.0% 2.3% 0.1% |
Properties | |
Coeff. of Exp. Strain Point Anneal Point Soften Point Density Youngs Mod. Refract Index Temp. Limits Max. Thermal Shock |
32.5 X 10-7cm/cm/°C 510°C 560°C 821°C 2.53 g/cm2 76 X 103 Kg/mm2 1.474 @ Sodium D Line 490°C(Extreme Service) 230°C(Normal Service) 160°C |