The AirTAC Airtac AIRTAC SCJ63 Standard Cylinder SCJ63X40-20 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. Ø63mm bore, 40mm nominal stroke, PT1/4 ports and adjustable end cushioning.
The SCJ63X40-20 is a double-acting, single-rod pneumatic cylinder with a 63 mm bore and a nominal 40 mm stroke, featuring a rear-cap adjusting screw that provides up to 20 mm of field-adjustable stroke-end reduction. This allows you to precisely dial in the piston stop position without removing the cylinder or adding external hard stops. At 0.5 MPa, it delivers 1559 N of push force and 1402 N on the pull stroke, making it a robust choice for clamping, pressing, and positioning tasks where the final stroke length must be tuned during commissioning or changeover.
The cylinder body has a length of 197 mm and uses a 20 mm diameter piston rod with an M16x1.5 male thread. It is equipped with PT1/4 ports and an adjustable air cushion to decelerate the piston smoothly at the end of travel. As a genuine AirTAC product, this SCJ unit is built for reliable service in filtered-air systems up to 1.0 MPa.
| Model | Airtac AIRTAC SCJ63 Standard Cylinder SCJ63X40-20 |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø63 mm |
| Nominal stroke | 40 mm |
| Stroke adjustment | Up to 20 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. |
| ×40 | 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.
During machine commissioning, the 20 mm adjustment range lets technicians fine-tune the actuator's end stop to match the exact mechanical interface, eliminating the need to shim or reposition the entire cylinder.
In clamping or pressing fixtures, the adjustable stroke can be periodically shortened to compensate for wear on tooling, contact pads, or the workpiece itself, maintaining consistent clamping force over time.
For packaging or assembly lines that handle multiple product sizes, the SCJ63X40-20 allows operators to quickly adjust the stroke end for a new format without swapping out the cylinder, reducing downtime.
Choose the SCJ63 when you need the force of a 63 mm bore—1559 N push at 0.5 MPa—and the flexibility to fine-tune the stroke end by up to 20 mm. If your application requires less force, the 50 mm bore SCJ50 provides 982 N push, while stepping up to an 80 mm bore SCJ80 yields 2513 N push for heavier loads. The adjustable stroke is ideal for applications where the exact stopping position must be set empirically, but if you need a fixed, repeatable stroke with no adjustment, a standard SC cylinder is a simpler and more cost-effective alternative.
This model is a direct replacement for another AirTAC SCJ63X40-20 cylinder with PT ports and basic mounting. For strokes of 300 mm or longer, be aware that the rod is subject to bending under high side loads; in such cases, use an external guide rail or switch to a guided cylinder to protect the rod and bearing from premature wear.
Adjustable-stroke checklist
At the standard operating pressure of 0.5 MPa, the cylinder produces 1559 N of pushing force and 1402 N of pulling force. The push force is higher because pressure acts on the full bore area, while the pull force is reduced by the area of the 20 mm piston rod. The maximum theoretical force at 1.0 MPa is 318 kgf.
You can, but the SCJ body is slightly longer due to the adjusting mechanism. It is a direct dimensional replacement only for another SCJ63X40-20. If you are replacing an SC63, ensure the extra length and the adjustable stroke feature are compatible with your machine's space and control requirements.
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