Rod actuator
THK EC (Economy cylinder) rod actuator
Economy rod-type electric cylinder with stepper or 50 W servo motor; series maximum 300 mm stroke, 450 mm/s, 266 N thrust and 40 kg horizontal load, repeatability +/-0.02 mm.
Key specifications
| Force (max) | 266 N |
|---|---|
| Stroke (max) | 300 mm |
| Linear speed (max) | 450 mm/s |
| Repeatability | 0.02 mm |
| Payload (max) | 40 kg |
| Motor | stepper (35/42 mm) or 50 W servo |
| Controller | TSC (stepper), TLC (servo) |
Summarised in our own words from THK CO., LTD.'s published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1 · Source 2
Notes on this data
Theoretical thrust with 6 mm lead.
Specify Motion is not affiliated with THK CO., LTD.. THK and EC (Economy cylinder) are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.
Typical applications
Alternatives that meet or exceed these figures
Engineers often come to us with a THK part number and leave with an alternative that is easier to source, quicker to deliver or a better fit for the machine. These 3 series from our supply network are the closest match on published figures.
Economical stainless-tube electric rod actuator in sizes 10, 15 and 20, aimed at replacing pneumatic cylinders for gating, sorting and diverting; SS1/SS2 options give an all-stainless, IP69K washdown build.
| Published maximum | EC (Economy cylinder) | ERD (incl. ERD-SS1 / ERD-SS2 stainless… |
|---|---|---|
| Force | 266 N | 2,224 N meets or exceeds |
| Stroke | 300 mm | 610 mm meets or exceeds |
| Speed | 450 mm/s | 1,016 mm/s meets or exceeds |
General-purpose electric rod actuator in six sizes with solid, bronze or ball screws and inline or reverse-parallel motor mounting; a broad pneumatic/hydraulic replacement workhorse.
| Published maximum | EC (Economy cylinder) | RSA-ST (standard thrust) |
|---|---|---|
| Force | 266 N | 17,917 N meets or exceeds |
| Stroke | 300 mm | 1,524 mm meets or exceeds |
| Speed | 450 mm/s | 3,124 mm/s meets or exceeds |
RSA-based rod actuator with integral hardened guide rods, bearings and a tooling plate, so it can carry side and offset loads without external guidance.
| Published maximum | EC (Economy cylinder) | GSA Guided Screw Actuator |
|---|---|---|
| Force | 266 N | 4,226 N meets or exceeds |
| Stroke | 300 mm | 914 mm meets or exceeds |
| Speed | 450 mm/s | 3,124 mm/s meets or exceeds |
Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.
What a rod actuator is
A rod actuator, sometimes called an electric cylinder, converts motor rotation into linear thrust through a screw and nut inside a tube, pushing a rod in and out like a pneumatic or hydraulic cylinder. The screw is usually a ball screw for efficiency, a roller screw for heavy loads or a lead screw for low cost. The rod is guided by bearings in the tube and an anti-rotation feature, and the motor is mounted inline or folded alongside through a belt or gear stage.
When engineers choose a rod actuator
Choose a rod actuator when the load is guided externally and needs pushing or pulling with controlled force, speed and position, typically to replace a pneumatic or hydraulic cylinder. It brings programmable positions, force control and energy savings. The trade-offs are side load and cost: the rod is not meant to carry significant radial load, and peak force for its size is lower than hydraulics. If the load needs carrying and guiding along the stroke, a rodless actuator or stage is usually better.
How to specify the THK EC (Economy cylinder)
Send these with your enquiry and an engineer can confirm the right EC (Economy cylinder) variant or an equivalent:
- Force: peak and continuous or RMS (N)
- Stroke (mm) and retracted length limits
- Speed and acceleration (mm/s, m/s²)
- Duty cycle or full motion profile
- Positioning repeatability (mm)
- Side load and mounting arrangement: trunnion, clevis or flange
- Motor and feedback preference, and environment (IP code, °C)
Common mistakes to avoid
- Sizing on peak force alone instead of RMS force over the cycle
- Rigidly mounting both ends so misalignment puts side load on the rod
- Ignoring critical speed and column buckling on long strokes
- Forgetting that a ball screw back-drives, so vertical loads need a brake
THK EC (Economy cylinder): frequently asked questions
What is the THK EC (Economy cylinder)?
Economy rod-type electric cylinder with stepper or 50 W servo motor; series maximum 300 mm stroke, 450 mm/s, 266 N thrust and 40 kg horizontal load, repeatability +/-0.02 mm. Published series figures include force 266 N, stroke 300 mm, linear speed 450 mm/s, repeatability 0.02 mm. It is made by THK CO., LTD.; Specify Motion can help source it or propose an equivalent.
Who makes the THK EC (Economy cylinder)?
The THK EC (Economy cylinder) is made by THK (THK CO., LTD.) and is listed here for engineers comparing options. Specify Motion is not affiliated with THK CO., LTD.; brand names are used only to identify the product.
What is the force of the THK EC (Economy cylinder)?
The published series maximum force is 266 N. Individual models and sizes in the EC (Economy cylinder) range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Is there an alternative to the THK EC (Economy cylinder)?
Yes. On published figures, Tolomatic ERD (incl. ERD-SS1 / ERD-SS2 stainless options) and Tolomatic RSA-ST (standard thrust) are the closest match from our supply network. An engineer confirms the fit against your application before recommending anything.
What is the difference between a rod actuator and a rodless actuator?
A rod actuator pushes and pulls a rod extending from its body, so it suits loads that are guided by the machine, much like a cylinder. A rodless actuator moves a carriage along the body and carries the load itself, which handles moment loads and long strokes within the actuator's own length. Pick rod for thrust and rodless for carrying.
Can an electric rod actuator replace a hydraulic cylinder?
Often, yes, especially where force needs are moderate and precise positioning, cleanliness or energy savings matter. Electric rod actuators with roller screws reach high forces, but extreme forces in a small envelope still favour hydraulics. Compare peak and continuous force, duty, shock loads and space, and check the motor and drive sizing as well as the screw.
Further reading: How to size a linear actuator · Hydraulic to electric actuator · Linear actuators
Other rod actuator series
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