Ajiya Heat Strengthened Glass is a heat treated glass with a residual surface compression greater than 3,500 psi and less than 10,000 psi, or edge compression greater than 5,500 psi and less than 9,700 psi. It is manufactured similarly to Ajiya Tempered Safety Glass, except this glass is cooled less rapidly. When broken, the break pattern will vary according to the surface compression.