Roller screw actuator
Exlar KX Series
Mid-force motorless planetary roller-screw actuator in three frame sizes that works with servo, stepper or DC motors via inline or parallel mounts, often used to replace pneumatic cylinders.
Key specifications
| Ingress protection | IP54S standard; IP65S with inline or parallel motor mount |
|---|---|
| Temperature | 0–65 °C |
| Force (max) | 15,600 N |
| Stroke (max) | 1,200 mm |
| Linear speed (max) | 833 mm/s |
| Screw lead | 5, 10 |
| Screw type | planetary roller screw |
| Sizes | KX60 (60 mm): 6.0 kN (5 mm lead) / 3.0 kN (10 mm lead); 417 / 833 mm/s; 5,000 rpm max input, KX75 (75 mm): 11.0-11.1 kN (5 mm) / 5.6 kN (10 mm); 333 / 666 mm/s; 4,000 rpm, KX90 (90 mm): 15.6 kN (5 mm) / 7.8 kN (10 mm); 250 / 500 mm/s; 3,000 rpm |
Summarised in our own words from Curtiss-Wright Actuation Group's published data; series maxima, individual models vary. Last checked 2026-10-29. Source 1 · Source 2 · Source 3
Notes on this data
Metric as printed. Stroke conflict: standard strokes 150/300/600/900 mm in product-page table, but features list and catalog ordering code include 1200 mm (48 in); catalog says consult sales for max allowable stroke. KX75 shown as 11.1 kN on page and 11.0 kN in catalog. Extended temperature -30 to 65 C (consult factory); storage -40 to 85 C. Backlash 0.10 mm; lead error G9 200 um/1000 mm. Forces are 'maximum force' (routine), not continuous.
Specify Motion is not affiliated with Curtiss-Wright Actuation Group. Exlar and KX Series 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 an Exlar 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.
Heavy-duty version of the RSA rod actuator with roller-screw options, matched angular-contact bearings and larger motor mounts, reaching 58 kN on size 64.
| Published maximum | KX Series | RSA-HT (high thrust) |
|---|---|---|
| Force | 15,600 N | 58,000 N meets or exceeds |
| Stroke | 1,200 mm | 1,524 mm meets or exceeds |
| Speed | 833 mm/s | 3,124 mm/s meets or exceeds |
High-force planetary roller-screw (and ball-screw) rod actuator up to 294 kN, positioned as a direct hydraulic cylinder replacement, with oil-cooled and food-grade versions.
| Published maximum | KX Series | RSX Extreme Force |
|---|---|---|
| Force | 15,600 N | 294,000 N meets or exceeds |
| Stroke | 1,200 mm | 1,500 mm meets or exceeds |
| Speed | 833 mm/s | 760 mm/s |
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 | KX Series | RSA-ST (standard thrust) |
|---|---|---|
| Force | 15,600 N | 17,917 N meets or exceeds |
| Stroke | 1,200 mm | 1,524 mm meets or exceeds |
| Speed | 833 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.
Other roller screw actuator series
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