The AirTAC Airtac SCJ63 Standard Cylinder SCJ63X250-40S 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. Ø63mm bore, 250mm nominal stroke, PT1/4 ports and adjustable end cushioning.
The SCJ63X250-40S is a double-acting, single-rod pneumatic cylinder that puts stroke-end fine-tuning directly on the machine. Its rear-cap adjusting screw provides a 40 mm adjustable range, letting you dial in the exact stop position without changing the cylinder or adding external hard stops. With a 20 mm piston rod and a push force of 1559 N at 0.5 MPa, it handles robust mid-range positioning tasks.
This model includes a built-in magnet (-S suffix), so CMSG/DMSG/EMSG reed and solid-state sensors clamp directly onto the tie-rod barrel for reliable end-of-stroke detection. The 28 mm air cushion decelerates the piston smoothly, and the PT1/4 ports keep plumbing simple. The body length A(SCJ) is 197 mm, making it a compact choice for adjustable-stroke applications in the 63 bore class.
| Model | Airtac SCJ63 Standard Cylinder SCJ63X250-40S |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø63 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 | M16×1.5 |
| 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, 28 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 | 1559 N | 1402 N |
| 0.7 MPa | 2182 N | — |
| Max (@1.0 MPa) | 318 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. |
|---|---|
| 63 | 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 adjustment screw allows technicians to fine-tune the actuator's end position on a new assembly line without swapping shims or mechanical stops, speeding up initial machine bring-up.
When a packaging line switches between product sizes, the SCJ63X250-40S can be quickly re-adjusted to change the push or placement stroke, reducing changeover time and the need for multiple fixed-stroke cylinders.
In a high-cycle clamping fixture, the adjustable stroke can be periodically advanced to compensate for wear on the clamp pads or the workpiece surface, maintaining consistent clamping force without replacing the cylinder.
Choose the SCJ63 when you need the 1559 N push force at 0.5 MPa and the ability to tweak the stroke end by up to 40 mm during commissioning or format changes. If your force requirement is lower, stepping down to a 50 mm bore reduces push force to 982 N; for higher demands, the 80 mm bore delivers 2513 N. This adjustable-stroke model is ideal when the exact stroke length is unknown at design time or may need periodic adjustment.
For a direct replacement, match the 63 mm bore, 250 mm nominal stroke, 40 mm adjust range, PT thread, and built-in magnet. Since the nominal stroke is 250 mm, rod buckling is generally not a concern in purely axial applications, but always check alignment to prevent side-load wear. If your application requires a fixed, non-adjustable stroke, the standard SC series is a simpler and more cost-effective alternative.
Adjustable-stroke checklist
The theoretical push force at 0.5 MPa is 1559 N, and the pull force on the retract stroke is 1402 N. At the maximum operating pressure of 1.0 MPa, the push force reaches 2805 N. The pull force is lower because the 20 mm piston rod reduces the effective area on the retract side.
Yes, if you need the added 40 mm stroke-end adjustability. The SCJ63X250-40S has the same 63 mm bore, 250 mm maximum stroke, and PT1/4 port as the fixed-stroke version. Ensure the slightly longer body length (197 mm) fits your mounting space and that you match the -S magnet option if you are using sensors.
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