MTS Series 204 & 244 Actuator Specifications

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Series 244 and 204 Linear Actuators & Accessories

Typical Applications:
  • Static testing
  • Cyclic tension-compression fatigue testing
  • MTS Series 204 & 244 Diagram ImageSeries 244 and 204 Linear Actuators are heavy duty, fatigue resistant, force generating actuators that operate under precise servo valve control in MTS closed-loop test systems.

    They can also be used in systems that require reliable precision force generation or accurate control of piston rod displacement. When equipped with the appropriate options and accessories, these actuators can be configured for testing materials, mechanical structures and components.



    Fixture attachment end of rod has a hardened, steel-threaded insert that provides an internal thread for mounting load cells, grips, or swivel bearings. (204.8, 204.09 and 244.51 have no inserts; instead, internal threads are machined directly into the piston rod end.)


    Large ports accommodate servo valves with flow ratings up to 90 rpm for high piston rod velocity. Inner oil distributing channels minimize oil flow restrictions. Higher flow ports are available.


    Large diameter, double ended piston has equal areas on both sides for balanced performance. Machined from a single piece of heat treated alloy steel, hard chrome plated, and ground to an 8 RMS finish to increase seal and bearing life. Because it's hollow, it's easy to install and permits accurate axial alignment of displacement transducers.


    Protect actuators from effects of high speed and high-mass loads (244.41 and 244.51 are not equipped with hydraulic cushions)


    Reinforced Teflon piston seal is configured to provide long life and low friction. (For high-speed cyclic testing applications, seal can be omitted.) Grooves on piston ensure adequate lubrication of surface during short-stroke, side loaded tests. Close tolerance fit provides effective viscous seal (does not apply to 204 actuator)


    High capacity nonmetallic bearings are bonded directly to piston rod end caps. Higher side load tolerance and resistance to failure and galling, seizure etc. (not standard with 204 actuators)


    High pressure seal and low pressure/wiper seal in front and rear end caps on piston rod. High pressure seal made of reinforced Teflon for long life and low friction. Hydraulic fluid leaks past high pressure seal for continuous bearing lubrication, and is then returned to the system hydraulic power supply via drain back ports.

    Low pressure/wiper seal provides two functions:

    1. Lower part wipes hydraulic fluid (passed by high pressure seal) from piston rod and guides fluid into drain back port.
    2. Upper part works as a scraper ring to minimize external contamination of seals and bearing.


    Displacement transducers (LVDT) provide stroke feedback signal to the system electronic control console. Can be configured with open housing for load frame applications, or closed housing for attaching a swivel or pedestal base. (Most structural or component testing use a closed housing to accommodate pedestal or swivel ends.)
    Servovalve mounting manifold must be included to mount a hydraulic fluid controlling servovalve to a series 244 actuator (series 204 and 242 actuators don't require mounting manifolds)


    Series 244/204 actuators consist of a basic cylinder assembly to which options can be added to adapt them to a variety of testing requirements and configurations. Standards options are:

  • Changing stroke length
  • Changing piston rod length
  • Special porting for flows greater than 90 rpm (340 l/m)
  • Standard stroke length is 4 inches for series 204 actuators, and 6 and 10 inches for series 244 actuators.

    MTS Series 204 & 244 Upper End and Base Mounting Holes Image

    Accessories - Series 204

    Accessories for the 204 actuator include a pedestal base, and a swivel head and base (same as that used for the 242 actuator)

    Accessories - Series 244

    Once the 244 actuator is configured with a basic cylinder assembly and options, other accessories for the actuator or fixture mounting can be added.

    Special piston rod end inserts provide compatible internal threads for connecting studs to mounting load cells, swivel heads, interface fixtures, etc. Either U.S. customary or SI metric threads are available.

    MTS Series 204 & 244 Specifications for Basic Cylinder Assembly Image

    1 Nominal force achieved with 21.0 MPa (3000psi) hydraulic pressure
    2 Stroke length does not include actuator cushions (specification A).
    3 This specification applies to standard length piston rod fully retracted
    4 204 series do not have thread inserts: standard thread size is U.S. Custom 1/2x20