The AirTAC Airtac SCJ40 Standard Cylinder SCJ40X125-40 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, 125mm nominal stroke, PT1/4 ports and adjustable end cushioning.
The SCJ40X125-40 is a double-acting, single-rod pneumatic cylinder with a 40 mm bore and a nominal stroke of 125 mm, featuring a rear-cap adjusting screw that provides up to 40 mm of field-adjustable stroke-end reduction. This allows precise mechanical fine-tuning of the piston stop position without replacing the cylinder or adding external hard stops, making it ideal for commissioning and format changeovers. At 0.5 MPa, it delivers 628 N of push force and 528 N of pull force, with a 16 mm diameter piston rod and PT1/4 ports.
This genuine AirTAC SCJ cylinder is built on a durable tie-rod platform, sharing the same force characteristics as the fixed-stroke SC series. The body length A(SCJ) is 185 mm, and the adjustable air cushion decelerates the piston smoothly at the end of travel. The standard TPU seal operates reliably from -20 to +70 °C, and the PT port threads ensure compatibility with common pneumatic fittings.
| Model | Airtac SCJ40 Standard Cylinder SCJ40X125-40 |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø40 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 | 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. |
| ×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.
The 40 mm adjustable stroke is perfect for dialling in the exact stop position during new machine commissioning, allowing engineers to compensate for assembly tolerances without machining custom spacers.
Quickly adapt the stroke end position for different product sizes on a packaging or sorting line. The rear screw adjustment makes format changes fast and repeatable without disconnecting air lines.
In high-cycle clamping or pressing fixtures, the adjustable stroke can be used to take up mechanical wear in tooling or seals over time, maintaining consistent contact force and part quality.
Choose the SCJ40X125-40 when you need a mid-range force actuator that can be quickly re-tuned on the machine. If your application requires more force, stepping up to the 50 mm bore SCJ50 series provides 982 N of push force at the same 0.5 MPa pressure. For applications needing a fixed, non-adjustable stroke, the standard SC40X125 is a direct alternative. This model uses a basic mounting configuration; for pivoting loads, consider the TC centre trunnion option (F-SC40TC) or the LB foot mount (F-SC40LB) for surface mounting. A direct replacement must match the 40 mm bore, 125 mm nominal stroke, 40 mm adjust range, and PT port threads.
Adjustable-stroke checklist
At the standard operating pressure of 0.5 MPa, the push force is 628 N and the pull force is 528 N. The maximum push force at 0.9 MPa is 1130 N. The pull force is lower due to the area of the 16 mm piston rod.
A screw in the rear end cap limits the retraction stroke. By turning this screw, you can shorten the effective stroke by up to 40 mm from the 125 mm nominal maximum. It adjusts the stroke end position mechanically and does not alter the cylinder's force or speed.
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