The AirTAC Airtac SCJ250 Standard Cylinder SCJ250X400-100 is a genuine double-acting SINGLE-ROD air cylinder with a rear-cap ADJUSTING SCREW: the stroke end is field-adjustable within a 100 mm range without swapping the cylinder. Ø250mm bore, 400mm nominal stroke, PT1" ports and adjustable end cushioning.
The SCJ250X400-100 is a heavy-duty, double-acting single-rod pneumatic cylinder from AirTAC's adjustable-stroke series. With a 250 mm bore and a 400 mm nominal stroke, it delivers a substantial 24544 N of push force at 0.5 MPa, making it suitable for the most demanding industrial positioning tasks. The defining feature is its rear-cap adjusting screw, which provides up to 100 mm of fine-tuning for the stroke end position, allowing on-machine adjustments without cylinder removal.
This ISO 6430 class tie-rod cylinder features a 50 mm diameter piston rod, a G1 inch port, and an M42x2 rod thread for robust, high-force connections. The integrated air cushion is 40 mm long, effectively decelerating large inertial loads. The body length A(SCJ) is 409 mm, and the operating speed range for this large bore is 30-500 mm/s. The default configuration includes a TPU seal for a standard temperature range of -20 to +70 °C and PT threads.
| Model | Airtac SCJ250 Standard Cylinder SCJ250X400-100 |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder (ISO 6430 class) |
| Bore size | Ø250 mm |
| Nominal stroke | 400 mm |
| Stroke adjustment | Up to 100 mm (rear adjusting screw) |
| Acting type | Double acting (single rod) |
| 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 SCJ (adjustable-stroke) datasheet. The rear adjusting screw sets the stroke end position; force is the same as the equivalent single-rod SC bore. Confirm against the product label before installation. Thread options: PT (standard) / G.
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 24544 N | 23562 N |
| 0.7 MPa | 34361 N | — |
| Max (@1.0 MPa) | 5006 kgf | |
SCJ is single-rod, so force matches the equivalent SC bore: push uses the full bore area, pull subtracts the rod area. Actual usable force is lower than theoretical due to friction and back-pressure; size with a safety margin.
| SCJ | Adjustable-stroke tie-rod cylinder series. |
|---|---|
| 250 | Bore size in mm. |
| ×400 | Nominal (maximum) stroke length in mm. |
| -100 | Adjustable-stroke range in mm (options 10/20/30/40/50/75/100). |
| -S | Optional built-in magnet for sensor position sensing. |
Related types: SC (single rod, fixed stroke), SCD (double rod), SCT (multi-position). SCJ mounting: Basic, FA, LB, TC, TCM1. Seals: TPU standard / H = Viton / N = NBR. Thread: blank = PT, G = G thread.
During die changes in large stamping presses, the 100 mm adjustment range allows operators to fine-tune the final pressing depth from the rear of the cylinder, accommodating different tooling heights without mechanical shimming.
In a sawmill, this cylinder positions a log stop. The adjustable stroke allows the mill to quickly switch between cutting lengths for different customer orders by simply turning the rear screw, rather than moving a fixed hard stop.
On a large structural welding fixture, the cylinder clamps a beam in place. As the clamp pads wear over thousands of cycles, the stroke can be incrementally extended via the adjusting screw to maintain consistent clamping force without replacing the pads immediately.
Select the SCJ250X400-100 when your application requires a massive push force of over 24000 N at standard shop air pressure, combined with the ability to precisely dial in the end-of-stroke position. If the force requirement is lower, stepping down to an SCJ200 bore would provide 15708 N of push force at 0.5 MPa, potentially reducing air consumption and physical footprint. For applications needing a fixed, unchangeable stroke, the standard SC series is a more economical choice.
This cylinder is a direct replacement for another AirTAC SCJ adjustable-stroke cylinder with a 250 mm bore, a 400 mm nominal stroke, a 100 mm adjustment range, and PT port threads. For strokes of this length, always evaluate side-loading on the 50 mm rod. If the load is not perfectly guided, an external guide rail or switching to a guided cylinder assembly is essential to prevent rod bending and premature seal failure.
Adjustable-stroke checklist
At the standard operating pressure of 0.5 MPa, the push force is 24544 N and the pull force is 23562 N. Since this is a single-rod cylinder, the pull force is lower due to the area of the 50 mm rod. The maximum push force at the 0.9 MPa limit is 44178 N.
No, the SCJ250X400-100 is not designed for position holding. The rear adjusting screw only sets the physical end-of-stroke limit and does not lock the piston in place. If air pressure is lost or the control valve is centered, the piston rod will drift or drop under load. A separate mechanical lock or pilot-operated check valve is required for static load holding.
Genuine AirTAC parts produced by AirTAC factory.
Covers non-human-caused product damage.
Standard models usually ship in 3-4 days.
Most inquiries answered within 7-8 hours.
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.