Shaft material: 40Cr(ASTM A5140) or 45#(ASTM 1045) steel.
Helix plate: ASTM A36 hot rolled plate, available in 3/8'' and 1/2'' thickness.
All helix leading edges sharpened and rock cut and 45 degrees.
Corrosion protection: ASTM A153, hot dipped zinc coating.
Efficient torque transfer, clear visual indicator of tension deflection.