The AirTAC Airtac SCJ40 Standard Cylinder SCJ40X65-20 is a genuine double-acting SINGLE-ROD air cylinder with a rear-cap ADJUSTING SCREW: the stroke end is field-adjustable within a 20 mm range without swapping the cylinder. Ø40mm bore, 65mm nominal stroke, PT1/4 ports and adjustable end cushioning.
The SCJ40X65-20 brings field-adjustable stroke control to the 40 mm bore class, delivering 628 N of push force at 0.5 MPa and up to 1130 N at 0.9 MPa. Its rear-cap adjusting screw provides 20 mm of stroke-end reduction, letting you fine-tune the piston stop without removing the cylinder or adding external hard stops. The 16 mm diameter piston rod and PT1/4 port thread keep it compatible with common pneumatic circuits.
This tie-rod cylinder uses a 21 mm air cushion to decelerate the piston smoothly, and the body length A(SCJ) measures 185 mm for the standard configuration. The adjustable stroke is ideal for commissioning trials, format changeovers, or taking up mechanical wear over time. As with all SCJ models, it is a double-acting, single-rod design, so push force exceeds pull force due to the rod area on the return side.
| Model | Airtac SCJ40 Standard Cylinder SCJ40X65-20 |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø40 mm |
| Nominal stroke | 65 mm |
| Stroke adjustment | Up to 20 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. |
| ×65 | Nominal (maximum) stroke length in mm. |
| -20 | 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-of-stroke position during machine commissioning without swapping cylinders. The 20 mm screw adjustment lets technicians dial in the exact stop point for grippers, clamps, or ejectors on the fly.
On packaging or assembly lines running multiple product sizes, the adjustable stroke allows operators to quickly reset the cylinder throw for different box heights or part lengths, reducing downtime between batches.
In high-cycle applications like pressing or stamping, mechanical stops can wear over time. The rear adjusting screw lets maintenance staff recover the precise stroke end without replacing the cylinder or shimming the mounting.
Choose the SCJ40 when your application needs roughly 600-1100 N of push force and the ability to dial in the stroke end on the machine. If you need more force, step up to the 50 mm bore SCJ50, which provides 982 N push at 0.5 MPa. For a simpler, fixed-stroke solution where adjustability is not required, the standard SC40 cylinder is a direct alternative. A replacement must match the 40 mm bore, 65 mm nominal stroke, 20 mm adjust range, PT port thread, and basic mounting style. For strokes of 300 mm or more, evaluate side-loading on the 16 mm rod and consider an external guide or a guided cylinder to prevent rod bending.
Adjustable-stroke checklist
At 0.5 MPa, the push force is 628 N and the pull force is 528 N. At the maximum operating pressure of 0.9 MPa, push force reaches 1130 N. Because it is a single-rod cylinder, push force is always greater than pull force due to the rod area on the return stroke.
Yes, provided the mounting and porting match. The SCJ40X65-20 has the same 40 mm bore, PT1/4 ports, and 16 mm rod as the SC40, but adds a rear adjusting screw for 20 mm of stroke-end reduction. The body is slightly longer to accommodate the screw mechanism. Ensure the extended rear cap length fits your machine envelope.
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