ER20 Spindle Unit Power Head Bearing for CNC Drilling Milling Machine 3000rpm. Professional Milling Groove Power Head ER20 3000 rpm for Lathe Spindle. The power milling head is a universal power component, which is combined with a milling machine or a power slide to supplement various types of support components, thereby forming various forms of combined milling machines. Used in various special machinery.Higher accuracy, better stability, more stable operation, double waterproof design structure. Isolate cutting fluid and dust during production and processing to ensure that the spindle head is in good condition in actual work (only some models have waterproof function). The spindle box is made of high toughness cast iron. After manual and natural double aging treatment, it is wear-resistant and not easily deformed. Model:ER20(60)-drilling waterproof. Rising Temperature:within 25 Degree Celsius. Spindle Material:20CrmnTi, carburizing heat treatment. 1X ER20(60)-drilling waterproof.