Heat slowly to 1450°F. hold 20 minutes per inch of greatest crosssection after tool reaches furnace temperature (minimum holding time – 20 minutes). Quench in water or 10% brine solution to 150°/200°F. Temper immediately 2 hours per inch of greatest cross-section at temperatures shown to achieve the desired hardness. W-1 Tool Steel is a general purpose waterhardening tool steel with a 1.00% Carbon content. It offers an excellent combination of physical properties with an outer case that is abrasion resistant in the 60 Rockwell “C” range with a soft, ductile inner core. W -1 is the easiest of all steels to machine with a machinability rating of 100 as a basis for comparison with other tool steels.