Originally Posted by
adbuett
A quick and dirty little calculation I did over in a thread in the hones section: An approximate thermal expansion coefficient for steel is 0.00000645 in/deg F. Using this generalization, a 3" razor will expand 0.00001935" per degree the temperature is raised. Say we go from 80 degrees room temp to 120 degree hot water. We have a delta T of 40, meaning that a 3" razor will expand 0.000774". A human hair is roughly 0.04" in diameter. So if you cover 40 degrees, your razor will be about 1/100th of a hair longer!