Airtac SCJ250 Standard Cylinder SCJ250X125-30S
The AirTAC Airtac SCJ250 Standard Cylinder SCJ250X125-30S is a genuine double-acting SINGLE-ROD air cylinder with a rear-cap ADJUSTING SCREW: the stroke end is field-adjustable within a 30 mm range without swapping the cylinder. Ø250mm bore, 125mm nominal stroke, PT1" ports and adjustable end cushioning.
- BoreØ250 mm
- Nominal stroke125 mm
- Stroke adjust-30 mm
- Port sizePT1"
- Rod threadM42×2
- CushionAdjustable, 40 mm
About the Airtac SCJ250 Standard Cylinder SCJ250X125-30S
The SCJ250X125-30S is a large-bore, double-acting single-rod pneumatic cylinder with a rear-cap adjusting screw that provides up to 30 mm of field-adjustable stroke-end retraction. With a 250 mm bore, it delivers a substantial 24544 N of push force at 0.5 MPa and 44178 N at the maximum operating pressure of 0.9 MPa, making it suitable for heavy-duty industrial positioning where the final stroke length needs fine-tuning during commissioning or format changes.
This ISO 6430 class tie-rod cylinder features a 50 mm diameter piston rod, a G1 inch port, and a 40 mm adjustable air cushion for smooth end-of-stroke deceleration. The built-in magnet (denoted by the -S suffix) allows for direct mounting of CMSG/DMSG/EMSG sensors along the barrel for contactless position feedback, simplifying integration into automated sequences without external switch rails.
Airtac SCJ250 Standard Cylinder SCJ250X125-30S Technical Specifications
| Model | Airtac SCJ250 Standard Cylinder SCJ250X125-30S |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder (ISO 6430 class) |
| Bore size | Ø250 mm |
| Nominal stroke | 125 mm |
| Stroke adjustment | Up to 30 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.
Theoretical Output Force (Ø250mm)
| 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.
Model Code: Airtac SCJ250 Standard Cylinder SCJ250X125-30S
| SCJ | Adjustable-stroke tie-rod cylinder series. |
|---|---|
| 250 | Bore size in mm. |
| ×125 | Nominal (maximum) stroke length in mm. |
| -30 | 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.
Where the Airtac SCJ250 Standard Cylinder SCJ250X125-30S Is Used
Press-Fit Depth Adjustment
In a heavy assembly press, the 30 mm adjustable stroke allows operators to quickly change the final press depth for different part batches without swapping the cylinder or adding mechanical hard stops.
Large Gate or Diverter Control
Controls a heavy material diverter gate on a conveyor. The adjustable stroke end compensates for wear on the gate seal over time, ensuring a tight seal without reprogramming the controller.
Commissioning Heavy Tooling
During the setup of a large welding fixture, the 30 mm adjustment range on this 24544 N cylinder is used to precisely find the optimal clamping position for a new part, saving significant setup time.
Is the Airtac SCJ250 Standard Cylinder SCJ250X125-30S the Right Cylinder?
Select the SCJ250 when you need high force and the ability to dial in the exact stroke end position on the machine. If your application requires a fixed, non-adjustable stroke, the standard SC250 is a more economical choice. For applications needing even higher push force, consider stepping up to a larger bore, though the SCJ250 is already at the top of the standard range. If the load must be guided, pair this cylinder with an external guide system, as the 125 mm stroke on a 50 mm rod can be susceptible to side-loading.
For a direct replacement, match an AirTAC SCJ250 adjustable-stroke cylinder with the same 250 mm bore, 125 mm nominal stroke, 30 mm adjustment range (-30), PT port thread, basic mounting, and the -S magnet option. Confirm that the mounting style and sensor type are compatible with your existing setup.
Adjustable-stroke checklist
- ✓ Need to fine-tune stroke on the line?
- ✓ Nominal stroke + adjust range (-30)
- ✓ Required force at your working pressure
- ✓ Port/thread type (PT/NPT/G)
- ✓ Magnet (-S) for sensors?
Installation & Maintenance Notes
- check Use clean air filtered to 40µm or finer.
- check Keep within 0.15 – 1.0 MPa operating pressure.
- check Set the rear adjusting screw, then lock it before running.
- check Adjust end cushion screws for smooth stops.
- check Use SCJ mounting accessory (FA / LB / TC / TCM1).
- check Installation by qualified personnel per AirTAC docs.
Airtac SCJ250 Standard Cylinder SCJ250X125-30S FAQ
The theoretical push force at the maximum operating pressure of 1.0 MPa is 5006 kgf. At the standard 0.5 MPa, it provides 24544 N of push force. The pull force is slightly lower at 23562 N due to the 50 mm piston rod reducing the effective area on the return stroke.
The rear cap has an integrated adjusting screw that acts as an internal, movable end-stop for the piston. By turning this screw, you can shorten the stroke end by up to 30 mm from the nominal 125 mm maximum. This is a mechanical adjustment for the stroke length only; it does not change the cylinder's force or speed.
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