The AirTAC Airtac SCJ50 Standard Cylinder SCJ50X125-40S 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. Ø50mm bore, 125mm nominal stroke, PT1/4 ports and adjustable end cushioning.
The AirTAC SCJ50X125-40S is a double-acting, single-rod pneumatic cylinder with a field-adjustable stroke end, offering a nominal 125 mm stroke that can be shortened by up to 40 mm via the rear adjusting screw. This model delivers a push force of 982 N at 0.5 MPa and features a 20 mm diameter piston rod with an M16x1.5 male thread, making it a robust choice for positioning tasks that require fine-tuning during commissioning or format changes.
Equipped with a built-in magnet (-S suffix), this cylinder is ready for direct mounting of CMSG, DMSG, or EMSG reed and solid-state sensors, enabling precise end-of-stroke detection without additional brackets. The tie-rod construction uses PT1/4 ports, a TPU seal for a standard -20 to +70 °C operating range, and an adjustable air cushion for smooth deceleration. Its body length A is 194 mm, providing a compact yet powerful solution for industrial automation.
| Model | Airtac SCJ50 Standard Cylinder SCJ50X125-40S |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø50 mm |
| Nominal stroke | 125 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, 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 | 982 N | 825 N |
| 0.7 MPa | 1374 N | — |
| Max (@1.0 MPa) | 200 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. |
|---|---|
| 50 | Bore size in mm. |
| ×125 | 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 end position of a stop gate or diverter on a new packaging line without re-drilling mounting holes, using the 40 mm adjustment range to perfectly align with product sizes.
Adjust the stroke end to take up mechanical wear on a clamp or press fixture over time, maintaining consistent contact pressure without replacing the cylinder.
Quickly reset the push stroke for different box heights on a case erector by turning the rear screw, eliminating the need for multiple fixed-stroke cylinders or hard stops.
Select the SCJ50X125-40S when you need a mid-range force of 982 N push at 0.5 MPa with the ability to dial in the stroke end on the machine. If your application requires more force, stepping up to the 63 mm bore provides 1559 N push; for a lighter, more compact solution, the 40 mm bore delivers 628 N. This adjustable-stroke model is ideal for tasks where the exact travel must be set empirically, unlike a fixed-stroke SC cylinder.
For direct replacement, match the 50 mm bore, 125 mm nominal stroke, and 40 mm adjustment range, ensuring the PT port thread and the -S magnet option are identical. If the cylinder must support a significant side load, particularly at this extended 125 mm stroke, consider adding an external linear guide or switching to a guided cylinder assembly to prevent rod bending and premature seal wear.
Adjustable-stroke checklist
The theoretical push force is 982 N at 0.5 MPa and 1767 N at 0.9 MPa. The pull force is lower due to the single 20 mm rod, providing 825 N at 0.5 MPa.
A screw in the rear cap limits the piston's retraction, allowing you to shorten the nominal 125 mm stroke by up to 40 mm. It sets the stroke end position and does not adjust the cylinder's speed or output force.
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