The nominal performance requirements for the wheel are:

• Ultimate tensile and Yield Strengths -- 
  60 ksi and 30ksi

• Elongation = 22%; Reduction = 30%

• Hardness -- 120 -163 BHN

• Surface Finish -- 250-500 RMS on as-cast surfaces

• Dimensional tolerances of +/- 0.003" on machined surfaces.

• A low carbon, high magnetic permeability steel is required for magnetic performance.