The AirTAC Airtac SCJ250 Standard Cylinder SCJ250X125-40S is a genuine double-acting SINGLE-ROD air cylinder with a rear-cap ADJUSTING SCREW: the stroke end is field-adjustable within a 40 mm range without swapping the cylinder. Ø250mm bore, 125mm nominal stroke, PT1" ports and adjustable end cushioning.
The AirTAC SCJ250X125-40S is a heavy-duty, double-acting single-rod cylinder with a 250 mm bore, delivering a substantial 24544 N of push force at 0.5 MPa. A rear-cap adjusting screw provides a 40 mm field-adjustable stroke-end range, allowing you to fine-tune the piston's stopping position without removing the cylinder. This model includes a built-in magnet, enabling direct mounting of CMSG/DMSG/EMSG sensors for reliable end-of-stroke detection.
Designed for demanding applications, this ISO 6430 class tie-rod cylinder uses a 50 mm diameter piston rod and PT1 inch ports. The adjustable air cushion, with a 40 mm length, decelerates the piston smoothly at the end of travel. Its body length A(SCJ) is 409 mm, providing a robust platform for high-force, precise positioning tasks where stroke-end adjustment is critical.
| Model | Airtac SCJ250 Standard Cylinder SCJ250X125-40S |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder (ISO 6430 class) |
| Bore size | Ø250 mm |
| Nominal stroke | 125 mm |
| Stroke adjustment | Up to 40 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. |
| ×125 | Nominal (maximum) stroke length in mm. |
| -40 | 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.
Fine-tune the final pressing depth on a large hydraulic or pneumatic press during die setup and commissioning, using the 40 mm adjustment range to achieve the exact material compression required without swapping out the massive cylinder.
Adjust the retracted position of a heavy-duty stop gate on a conveyor line for handling large pallets or steel coils, accommodating different product widths by simply turning the rear adjusting screw.
Set the precise clamping stroke for different workpiece families in a large machining center or welding fixture, using the sensor-ready magnet to confirm the clamp has reached its adjusted position every cycle.
Select the SCJ250X125-40S when your application requires immense push force and the ability to dial in the stroke end position on the machine. If you need even more force, stepping up is not possible as this is the largest bore in the series. For a lighter, more compact solution, the SCJ200 bore provides 15708 N of push force at 0.5 MPa. This adjustable-stroke model is ideal for commissioning and format changes; however, if your stroke length is permanently fixed, the standard SC fixed-stroke cylinder is a more economical choice. For direct replacement, match the 250 mm bore, 125 mm nominal stroke, 40 mm adjust range, PT port thread, and the built-in magnet (-S). At this stroke length, ensure the rod is not subjected to significant side loads, or use an external guide system to prevent bending and premature seal wear.
Adjustable-stroke checklist
At the standard 0.5 MPa operating pressure, the push force is 24544 N and the pull force is 23562 N. The push force is higher because the single piston rod reduces the effective area on the return stroke. The maximum theoretical force at 1.0 MPa is 5006 kgf.
The rear-cap screw sets the stroke end position, shortening the piston's travel by up to 40 mm from the nominal 125 mm maximum. It is a direct dimensional replacement for another SCJ250X125-40S cylinder. It can replace a fixed-stroke SC cylinder if you need field adjustability, but you must ensure the SCJ's longer body length A(SCJ) of 409 mm fits your mounting space.
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