Crusader Silver Steel is a high carbon bright steel, precision ground to very close tolerances. Close control of chemical analysis, particularly the chromium content, ensures optimum strength and hardenability and a consistent response to heat treatment. Crusader Silver Steel is supplied in the annealed condition and is readily machinable. All ends are individually deburred, which ensures safety during handling and protects other pieces from scratching. Silver steel pieces are individually dipped in a lanolin-based solution to guard against corrosion. Length: 330mm Tolerances: under 25mm dia + 0.000 and - 0.010mm, over 25mm dia and above + 0.000 and - 0.020mm Heat Treatment: for maximum hardness (66 Rockwell C or 950 VPN) heat to 770°C - 790°C (1420°F - 1450°F). Soak until uniformly heated then quench in clean water or preferably 10% brine solution. The most satisfactory and efficient method is to heat in a salt bath and it is advisable to control the temperature carefully. The use of a pyrometer is recommended. If a muffle furnace is used, the atmosphere should be slightly reduced to minimise scaling and to avoid spots. Soak for a minimum of one hour at the following temperatures immediately after hardening: Temperature Range Hardness 150°C (302°F) - 63/65 RC 200°C (392°F) - 60/62 RC 250°C (482°F) - 59/61 RC 300°C (572°F) - 55/57 RC Annealing: heat to 760° - 780°C (1400° - 1470°F). Soak for one hour per 25mm of section and cool slowly in the furnace.