The AirTAC Airtac SCJ250 Standard Cylinder SCJ250X125-20 is a genuine double-acting SINGLE-ROD air cylinder with a rear-cap ADJUSTING SCREW: the stroke end is field-adjustable within a 20 mm range without swapping the cylinder. Ø250mm bore, 125mm nominal stroke, PT1" ports and adjustable end cushioning.
The SCJ250X125-20 is a double-acting, single-rod tie-rod cylinder engineered for heavy-duty applications requiring fine-tuned stroke-end positioning. With a 250 mm bore and a 50 mm piston rod, it delivers a substantial 24544 N of push force at 0.5 MPa, making it suitable for pressing, clamping, and large-format material handling. The rear-mounted adjusting screw provides up to 20 mm of retraction from the nominal 125 mm stroke, allowing operators to dial in the exact end position without dismounting the cylinder.
This ISO 6430 class cylinder features a 40 mm adjustable air cushion to decelerate high-inertia loads smoothly. The body length A(SCJ) is 409 mm, and it uses a PT1 inch port with an M42x2 rod thread. Operating on filtered air from 0.15 to 1.0 MPa, it is built for robust industrial environments where precise, repeatable motion is critical.
| Model | Airtac SCJ250 Standard Cylinder SCJ250X125-20 |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder (ISO 6430 class) |
| Bore size | Ø250 mm |
| Nominal stroke | 125 mm |
| Stroke adjustment | Up to 20 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. |
| -20 | 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 bottom-dead-center of a hydraulic-pneumatic press tool by adjusting the stroke end with the rear screw, compensating for tool wear or material thickness variations without reprogramming the press controller.
Use as an adjustable end-stop on a conveyor for large pallets or steel plates. The 20 mm adjustment range allows operators to quickly change the stopping position for different product sizes during batch changeovers.
Precisely set the open/close stroke of a large industrial gate or butterfly valve. The adjustable stroke ensures the valve disc seats perfectly without over-travel, protecting the seat and actuator from mechanical damage.
Choose the SCJ250 bore when your application demands a push force around 24544 N at standard shop air pressure. If your load requires less force, stepping down to the 200 mm bore reduces push force to 15708 N at 0.5 MPa, saving energy and physical space. For applications needing a fixed, non-adjustable stroke, the standard SC250 cylinder is a simpler alternative without the rear adjustment mechanism. For a direct replacement, match a genuine AirTAC SCJ cylinder with a 250 mm bore, 125 mm nominal stroke, a 20 mm adjustment range, and PT port threads. Since this is a 125 mm stroke on a large bore, rod buckling is not a primary concern, but always ensure the load is guided externally if significant side forces are present.
Adjustable-stroke checklist
At the standard operating pressure of 0.5 MPa, this cylinder produces 24544 N of push force and 23562 N of pull force. The maximum push force at the 0.9 MPa operating limit is 44178 N. The theoretical force at 1.0 MPa is 5006 kgf, but the cylinder should not be operated above 1.0 MPa.
Yes, if you need to fine-tune the stroke end position. The SCJ250X125-20 has the same mounting footprint and force characteristics as the fixed-stroke SC250X125 but includes a rear adjusting screw that shortens the stroke by up to 20 mm. Ensure your machine has clearance for the slightly longer body length A(SCJ) of 409 mm and accepts the PT1 inch ports.
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