The AirTAC Airtac SCJ250 Standard Cylinder SCJ250X300-40 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, 300mm nominal stroke, PT1" ports and adjustable end cushioning.
The SCJ250X300-40 is a double-acting, single-rod pneumatic cylinder from AirTAC's heavy-duty tie-rod series, engineered for applications where the stroke end position must be fine-tuned on the machine. A rear-cap adjusting screw provides a 40 mm field-adjustable range, allowing operators to shorten the 300 mm nominal stroke without dismounting the cylinder or adding external hard stops. This ISO 6430 class cylinder delivers a substantial 24544 N of push force at 0.5 MPa, making it suitable for pressing, clamping, and material handling tasks that demand high force.
With a 50 mm diameter piston rod and a G1" port, the SCJ250X300-40 is built for robust industrial use. The body length A(SCJ) is 409 mm, and it features an adjustable air cushion of 40 mm to decelerate the piston smoothly at the end of its travel. The standard operating pressure ranges from 0.15 to 1.0 MPa, with a proof pressure of 1.5 MPa. This model is configured with the default TPU seals for a temperature range of -20 to +70 °C and standard PT threads.
| Model | Airtac SCJ250 Standard Cylinder SCJ250X300-40 |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder (ISO 6430 class) |
| Bore size | Ø250 mm |
| Nominal stroke | 300 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. |
| ×300 | 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 for bearing or bushing insertion on an assembly line. The 40 mm adjustable stroke allows operators to compensate for part tolerance variations without changing the tooling, ensuring consistent press-fit quality.
Act as an adjustable end-stop for pallets or heavy steel plates on a conveyor. The stroke can be quickly dialed in during a format changeover to accommodate different product sizes, leveraging the cylinder's 24544 N push force to halt moving loads.
Used in a large welding fixture where the clamp's grip point wears over time. The rear adjusting screw provides a simple way to take up the wear and restore full clamping force without replacing the entire cylinder, minimizing downtime.
Select the SCJ250X300-40 when your application requires a high-force, field-adjustable stroke end within a 40 mm window. If the force requirement is lower, stepping down to the 200 mm bore SCJ series provides 15708 N of push force at 0.5 MPa, which may be a more cost-effective and compact solution. For applications needing a fixed, non-adjustable stroke, the standard SC250X300 single-rod cylinder is a direct alternative with identical mounting and force characteristics. Given the 300 mm stroke, ensure the rod is adequately supported against side loads; an external guide rail or a switch to a guided cylinder is recommended to prevent rod bending and premature seal wear. A direct replacement must match the 250 mm bore, 300 mm nominal stroke, 40 mm adjustment range, PT port thread, and basic mounting configuration.
Adjustable-stroke checklist
The rear cap has an integrated adjusting screw that limits the piston's retraction. By turning this screw, you can shorten the stroke end by up to 40 mm from the nominal 300 mm maximum. This is a mechanical stop for stroke adjustment, not a force or speed controller.
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 it acts on the full 250 mm bore area, while the pull force is reduced by the area of the 50 mm piston rod.
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