The AirTAC Airtac SCJ63 Standard Cylinder SCJ63X125-50S is a genuine double-acting SINGLE-ROD air cylinder with a rear-cap ADJUSTING SCREW: the stroke end is field-adjustable within a 50 mm range without swapping the cylinder. Ø63mm bore, 125mm nominal stroke, PT1/4 ports and adjustable end cushioning.
The SCJ63X125-50S is a double-acting, single-rod pneumatic cylinder that puts precise stroke-end tuning at your fingertips. With a 63 mm bore, it delivers 1559 N of push force at 0.5 MPa, while the rear adjusting screw lets you shorten the 125 mm nominal stroke by up to 50 mm directly on the machine. Its 20 mm piston rod and 28 mm air cushion length suit medium-duty positioning tasks where commissioning trials or format changes demand quick, tool-free adjustment.
This model includes a built-in magnet (-S suffix), so you can clamp CMSG, DMSG, or EMSG reed and solid-state sensors directly onto the tie-rod barrel for reliable end-of-stroke detection. The standard TPU seal operates from -20 to +70 °C, and PT1/4 ports keep plumbing simple. The SCJ body length A is 197 mm, making it a compact solution when you need field-adjustable stroke without adding external hard stops.
| Model | Airtac SCJ63 Standard Cylinder SCJ63X125-50S |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø63 mm |
| Nominal stroke | 125 mm |
| Stroke adjustment | Up to 50 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. |
| ×125 | Nominal (maximum) stroke length in mm. |
| -50 | 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 clamp or stop during machine commissioning without removing the cylinder. The 50 mm adjustment range lets technicians dial in the exact stroke required for a new fixture.
Adjust the stroke of a diverter gate or pusher on a packaging line when switching between product sizes. The rear screw provides a repeatable mechanical stop that is faster to change than reprogramming a servo axis.
Take up mechanical play or seal wear in a pressing or clamping station over time. A small turn of the adjusting screw restores the original tooling position without replacing the cylinder or adding shims.
Choose the SCJ63 when you need the 1559 N push force at 0.5 MPa that a 63 mm bore provides. If your force requirement is lower, stepping down to a 40 mm bore (628 N push) saves space and air consumption; for higher force, the 80 mm bore delivers 2513 N. This adjustable-stroke cylinder is the right pick when the final stroke length must be dialed in during setup or changed periodically—unlike a fixed-stroke SC, which requires swapping the cylinder or adding external stops. For a direct replacement, match the 63 mm bore, 125 mm nominal stroke, 50 mm adjust range, PT port thread, basic mounting, and the built-in magnet. If your application involves significant side loads, consider an external guide rail or a guided cylinder to protect the rod bearing.
Adjustable-stroke checklist
At the standard 0.5 MPa operating pressure, the push force is 1559 N and the pull force is 1402 N (the difference is due to the 20 mm single piston rod). At the maximum operating pressure of 1.0 MPa, the theoretical push force reaches 3118 N. Always size your cylinder based on the required force at your specific working pressure.
Yes, if you need the ability to fine-tune the stroke end. The SCJ63X125-50S has the same 63 mm bore, PT1/4 ports, and mounting footprint as an SC63, but its body length A is 197 mm. Ensure the 50 mm adjustment range suits your stroke requirement. The built-in magnet (-S) must also be matched if your existing setup uses sensors.
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