When sourcing a buffing machine, you must prioritize the Motor Power (HP/Watts) and Rotational Speed (RPM). For industrial metalwork, a motor of at least 1.5 HP to 3 HP is recommended to maintain torque under pressure. Look for Variable Speed Control features, as different materials require specific speeds (e.g., lower RPM for plastics to prevent melting, higher RPM for stainless steel). Additionally, verify the Spindle Diameter and Length to ensure compatibility with your existing buffing wheels and to provide enough clearance for large workpieces.