What is the difference between DURAN, Boro 3.3, Boro 4.1 and other types of glass?
DURAN is a borosilicate glass 3.3. The term 3.3 represents the linear thermal coefficient of expansion. The lower this is, the more resistant the glass is to variations in temperature. = 3.3 therefore means that the glass expands by 3.3 *10-6 units of length per kelvin, in a temperature range from 20C to 300C. With large coefficients of expansion temperature differences cause stresses in the glass when it is heated and this can result in breakage.
