The day I visited the shop I was able to see the "quenching" process of five Wisco Cleavers. The stainless steel blades are heated to 1,975 degrees-Fahrenheit for ten minutes. They're carefully removed one at a time then placed between two heavy aluminum blocks where the heat is "sucked out" by shooting compressed air in the space between hardening the steel. The blade is dipped into a liquid nitrogen bath at -300 degrees-Fahrenheit. From there the blades are placed into a 375 degree-Fahrenheit oven in Schroeder's home kitchen which he explains "tempers the steel back to a more tough state so it is still hard but not so hard that it will break during use."