Maintenance free because there is no mechanical defacement like a brush for a dc motor
NEMA 34 Step motor is a Large size motor with high torque and speed, It's Suitable for Conveyors, Pharma Labeling Machines, Packaging Machines, Mask Making, Ventilator units, CNC Router, Drilling & Tapping, etc. applications, Its flange size is 86mm with 12.7mm (With Key-way) & 14mm Shaft Diameter.