The AirTAC Airtac SCD Standard Cylinder SCD250X400 is a genuine double-acting DOUBLE-ROD air cylinder: the Ø50mm piston rod extends from BOTH end caps, giving equal effective area — and therefore equal force — in push and pull. Ø250mm bore, 400mm stroke, PT1" ports and adjustable end cushioning.
The SCD250X400 is a heavy-duty double-rod pneumatic cylinder engineered for applications demanding identical force and speed in both directions. With a 250 mm bore and 50 mm through-rod, it generates a substantial 23562 N of thrust each way at just 0.5 MPa, rising to 42412 N at the maximum operating pressure of 0.9 MPa, making it suitable for large-scale symmetrical tooling.
This tie-rod cylinder features a 400 mm stroke and an adjustable air cushion (40 mm length) at both ends to decelerate high-inertia loads. The double-rod construction provides superior guidance and anti-rotation compared to a single-rod cylinder, and the exposed rear rod is ideal for mounting external stroke sensors or a mechanical stop. The body length A(SCD) is 435 mm, and the standard port is PT1".
| Model | Airtac SCD Standard Cylinder SCD250X400 |
|---|---|
| Series | SCD double-rod tie-rod cylinder (ISO 6430 class) |
| Bore size | Ø250 mm |
| Rod diameter | Ø50 mm (both ends) |
| Stroke | 400 mm |
| Rod configuration | Double rod — rod through both caps |
| Acting type | Double acting |
| Port size | PT1" |
| Rod thread | M42×2 |
| Fluid | Air (filtered by 40µm element) |
|---|---|
| Operating pressure | 0.15 – 1.0 MPa |
| Proof pressure | 1.5 MPa |
| Temperature | -20 to +70 °C |
| Speed range | 30 – 500 mm/s |
| Cushion | Adjustable, 40 mm |
| Max stroke | Up to 1500 mm |
Specifications follow the official AirTAC SCD (double-rod) datasheet. Because the rod runs through both caps, the effective area is (bore² − rod²) in both directions. Confirm against the product label before installation. Thread options: PT (standard) / G.
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 23562 N | 23562 N |
| 0.7 MPa | 32987 N | 32987 N |
| Max (@1.0 MPa) | 4805 kgf | |
Push and pull are EQUAL on a double-rod cylinder — both chambers lose the rod area, so effective area = (bore² − rod²) each way. Actual usable force is lower than theoretical due to friction and back-pressure; size with a safety margin.
| SCD | Double-rod tie-rod cylinder series (rod out both ends). |
|---|---|
| 250 | Bore size in mm. |
| ×400 | Stroke length in mm. |
| -S | Optional built-in magnet for sensor position sensing. |
Related types: SC (single rod), SCJ (adjustable stroke), SCT (multi-position). SCD mounting: Basic, FA, LB, TC, TCM1. Seals: TPU standard / H = Viton / N = NBR. Thread: blank = PT, G = G thread.
Operates identical pressing or forming tools mounted on both ends of the through-rod, doubling throughput with perfectly balanced force and speed in each direction.
Applies a controlled, equal tensile force to large cables, belts, or structural members by anchoring one rod end and using the other to pull, with the 23562 N force at 0.5 MPa.
Drives a heavy transfer shuttle between two stations with identical acceleration and deceleration profiles in both directions, using the rear rod for a position feedback flag.
Choose the SCD250X400 when your application requires balanced, high-force actuation from both ends of the piston. If your force requirement is lower, stepping down to the SCD200 bore reduces the output to 15080 N at 0.5 MPa, which may be sufficient and offers a more compact footprint. This double-rod cylinder is the right choice over a single-rod SC model when you need to attach tooling or a sensor flag to the rear rod, or when the inherent anti-rotation of the through-rod is beneficial.
For a direct replacement, match the 250 mm bore, 400 mm stroke, PT1" port thread, and basic mounting configuration. At this 400 mm stroke, be mindful of potential rod bending under high side loads; the through-rod design offers better support than a single rod, but for significant off-axis forces, an external guide rail or a dedicated guided cylinder is the safer engineering choice.
Double-rod checklist
Because it is a double-rod cylinder, the push and pull forces are identical. The effective piston area is the same on both sides. At 0.5 MPa it produces 23562 N, at 0.7 MPa it produces 32987 N, and at the maximum operating pressure of 0.9 MPa it delivers 42412 N.
Select the SCD when you need to mount tooling, a stopper, or a sensor target on the rear rod, or when you require perfectly equal force and speed in both directions. The through-rod also provides better inherent guidance and anti-rotation than a single-rod SC cylinder, which is useful for maintaining tool alignment.
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