The AirTAC Airtac SCJ40 Standard Cylinder SCJ40X250-40S 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. Ø40mm bore, 250mm nominal stroke, PT1/4 ports and adjustable end cushioning.
The SCJ40X250-40S is a double-acting, single-rod pneumatic cylinder that provides a 250 mm nominal stroke with a 40 mm rear-cap adjusting screw for fine-tuning the stroke end position. Operating at 0.5 MPa, it delivers 628 N of push force and 528 N on the pull stroke, making it a practical workhorse for medium-duty linear tasks where the final stop point needs to be dialed in during commissioning or changeover.
This model includes a built-in magnet (-S suffix) for direct mounting of CMSG/DMSG/EMSG sensors, enabling precise end-of-stroke or mid-stroke position feedback without external brackets. The 16 mm diameter piston rod and PT1/4 port ensure reliable air flow, while the 21 mm air cushion at each end provides smooth deceleration for the 185 mm body length (A dimension).
| Model | Airtac SCJ40 Standard Cylinder SCJ40X250-40S |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø40 mm |
| Nominal stroke | 250 mm |
| Stroke adjustment | Up to 40 mm (rear adjusting screw) |
| Acting type | Double acting (single rod) |
| Port size | PT1/4 |
| Rod thread | M12×1.25 |
| 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 – 800 mm/s |
| Cushion | Adjustable, 21 mm |
| Max stroke | Up to 1200 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 | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 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. |
|---|---|
| 40 | Bore size in mm. |
| ×250 | 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.
The 40 mm adjust range lets technicians fine-tune the actuator's end-stop on a new assembly line without swapping shims or hard stops, cutting setup time.
Quickly adapt a pusher or diverter stroke for different box sizes on a packaging conveyor by turning the rear adjusting screw, eliminating mechanical rework.
In clamping or pressing fixtures, the adjustable stroke can be extended slightly over time to compensate for pad wear, maintaining consistent clamping force.
Choose the SCJ40X250-40S when you need a field-adjustable stroke end within a 40 mm window on a 250 mm base stroke. If your force requirements increase, stepping up to the 50 mm bore (SCJ50) provides 982 N of push force at the same 0.5 MPa pressure. For applications that do not require stroke adjustability, the fixed-stroke SC40 cylinder offers a simpler, cost-effective alternative. A direct replacement must match the 40 mm bore, 250 mm nominal stroke, 40 mm adjust range, PT port thread, and the -S magnet option.
At a 250 mm stroke, side-loading is a key consideration. Ensure the load is guided externally or use a rod-alignment coupler to prevent bending moments on the 16 mm rod. If the application involves significant off-axis loads, consider a guided cylinder instead.
Adjustable-stroke checklist
A screw in the rear cap sets the retracted end position of the piston. Turning it changes where the stroke ends within a 40 mm range, so the effective stroke can be set anywhere from 210 mm to 250 mm without changing the cylinder body.
At the standard 0.5 MPa operating pressure, it generates 628 N pushing and 528 N pulling. At the maximum 1.0 MPa pressure, the theoretical push force reaches 128 kgf. The push force is higher because the rod reduces the effective piston area on the pull side.
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