THERMAL SHOCK VS TENSILE STRENGTH: A COMPARISON STUDY
It is a popular fallacy among consumers of quartz (fused quartz) to equate its thermal shock resistance to its tensile strength. In reality this is far from the truth. Quartz actually has significantly less mechanical strength than glass (borosilicate). So why does everyone believe it to be stronger? We believe this erroneous thought process is derived from the extreme temperature differentiation (thermal shock) the fused quartz can withstand that borosilicate can not. Users that torch quartz know that it would be detrimental to torch their glass rig, so the impression is that quartz is strong while glass is fragile.
Many users that break a quartz product from an accidental drop, are under the impression that the quartz should have had more tensile strength because it is quartz. These same users would probably be surprised to know that quartz is significantly more likely to shatter on impact than borosilicate would be in the same scenario. This is because of the different mechanical properties between fused quartz and borosilicate (glass).
For comparison lets look at the properties of both. For each property being compared, the top bar is fused quartz and the bottom bar is borosilicate glass.