H

Heat resistant Glass
Glass which has a low coefficient of expansion and which is therefore less liable to thermal shock. Borosilicate glass is the most common type of heat resistant glass.
Hydrofluoric Acid
A highly corrosive acid which dissolves glass.
Heat-Absorbing Glass
Glass (usually tinted) formulated to absorb an appreciable portion of solar energy.
Heat-Strengthened Glass
Non-safety heat-strengthened glass with a surface compression between 3,500 and 7,500 psi and an edge compression of 5,500 psi or greater. It is approximately two times stronger than regular annealed glass of the same thickness. Its break pattern is similar to annealed glass. Available from Bendheim for special applications.
Heat Treated Glass
Term can be used for both tempered glass (safety) and heat-strengthened glass (non-safety).