Flask, Erlenmeyer, standard ground mouth

MATERIAL BOROSILICATE 3.3 
3.3 borosilicate glass is a low alkali borosilicate composition. It is virtually free of magnesia-lime-Zinc group and contains
only traces of heavy metals. 
Chemical Composition: 
81% in weight SiO2
13.0% in weight B2O3
4% in weight Na2O
Thermal Properties:
Coefficient of Linear Expansion: 32,5x10-7 ºC
Strains Point: 515ºC
Annealing Point: 565ºC
Softening Point: 820ºC
Specific Heat: 0,2
Thermal Conductivity (Cal/cm3/ºC/Sec): 0,0027 
Chemical Durability: These Glassware is highly resistance to water, neutral and acid solutions, concentrated on acids and
their mixtures as well as to chloride, bromine, iodine, and organic matters. Even during extended period of reaction and at
temperatures above 100° C, its chemical resistance exceeds of most metals and other materials. It can withstand repeated
dry and wet sterilization without surface deterioration and subsequent contamination. Resistance to attack of various
chemicals is shown under. Only hydrofluoric acid, very hot phosphoric acid and alkaline solutions increasingly attack the
glass surface with rising concentration and temperature