Yes I broke one when I splashed some water on it. But never just because. Drastic temp changes will do it before just heat. But my cups are in good shape and no cracks. When these cups are cracked it is more likely to break. The two on the outside are lab ware from pryex. I use them to put my sprues in and reheat. They are thinner and keep the sprues warmer till they are reheated. The thicker pyrex cups retain more heat so I just leave those there after the first heat up.
Stump Hunter Anything that does not let the temp drop will work. Not really sure about a hot plate though. Frank

