Freezing is a reference to cryogenic processing. Basically the parts are dunked in a very cold liquid (Nitrogen) and allowed to stabalize at that temp for a period of time. The science is that this "sets" the crystaline structure of the metal's molecules. Metal is sort of like wood that you can adjust the grain in for lack of a better analogy. I haven't had much experience with the process to be very knowlegeable on it but have heard of people freezing golf clubs, rotors and other stuff in the interest of getting the metal to "behave" better. I probably should read up on the process in case I come across a client with a need.