Gauges 010-013-017-026-036-046 Blue Steel strings are the world's first Cryogenically-processed strings. Starting with the very finest quality materials, Blue Steel strings are frozen to minus 320 degrees Fahrenheit, and then held there for an exact period of time. Finally, they are slowly and carefully brought back to their original temperature. This unique Cryogenic treatment realigns the molecular structure of the string, giving Blue Steel more highs and lows, a longer life, and a greater ability to stay in tune.