Pro Series® cones are made from 4150 pre-hardened alloy steel. They are heat-treated with a permanently infused surface hardness to Vickers 1880 (75+ Rockwell C), with a diffusion zone (approx. RC 60) and an RC 28-32 core hardness. Their surface hardness withstands the 72 hour salt spray corrosion test under ASTM B117 conditions, this hardness reduces surface flaking and galling. Pro Series® cones are taper ground to a maximum of .0001 concentricity for long wearing spindle fit, superior accuracy, and no vibration. This product is 100% made in the USA.
This product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.For more information: www.P65Warnings.ca.gov