Parker Hydraulic Group
M Series Hydraulic Rotary Actuators

Designed to meet steel mill specifications. These non-tie rod units incorporate a range of features to provide heavy duty service dependability.


  • Heavy Duty Mill Cylinder Construction
  • Tapered Roller Bearings
  • SAE Ports
  • Bronze Rack Bushings and Wear-Pak® Pistons
  • Large Diameter Chrome Alloy Steel Pinion

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The larger than normal heat treated pinions provide low tooth contact pressures and permit hollow shaft configurations with bore sizes capable of transmitting full operating torques, including shock loadings. In order to negate the chances of galling or scoring of the cylinder barrels, the Series M units are fitted with wear ring bushings that provide full support and eliminate the possibility of contact between cylinder and piston. The use of large diameter, tapered roller bearings on the pinion permit the actuator to absorb considerable thrust, radial and overhung loads. 

For ease of maintenance, all pressure seals on Series M can be inspected or replaced without removing the actuator from the customer’s shaft. To ensure shipment of only the highest quality product, each actuator is fully tested and has an individual test sheet completed before final painting and shipment.

Standard Rotations: 90°, 180°, 360°

Maximum Operating Pressure: 3,000 psi (207 Bar) hydraulic

Rotational Tolerance: -0°, +2°

Output Torques: 15,000 to 50,000 lb-in @ 3,000 psi (204 Bar)

Operating temperature range: 

  • Nitrile Seals -40 to 180°F (-40 to 82°C)
  • Fluorocarbon Seals -20 to 250°F (-29 to 121°C)

Mounting Orientation: Unrestricted

Standard Timing: Keyway in 12:00 Position at Midstroke

Housing: Heavy Duty Ductile Iron (Units up to 1000M); Steel Weldments (Units larger than 1000M)