The AirTAC Airtac SCJ50 Standard Cylinder SCJ50X40-30LB is a genuine double-acting SINGLE-ROD air cylinder with a rear-cap ADJUSTING SCREW: the stroke end is field-adjustable within a 30 mm range without swapping the cylinder. Ø50mm bore, 40mm nominal stroke, PT1/4 ports and adjustable end cushioning.
The SCJ50X40-30LB is a 50 mm bore, double-acting single-rod cylinder with a field-adjustable stroke end, letting you fine-tune the 40 mm nominal stroke by up to 30 mm using the rear-cap screw. At 0.5 MPa it delivers 982 N push and 825 N pull, driven through a 20 mm diameter rod, with air cushioning over the final 21 mm of travel to decelerate the piston.
Built on the proven SC tie-rod platform with a 194 mm body length A, this model includes the LB foot-mount bracket (order code F-SC50LB) for secure surface mounting. The standard PT1/4 port and TPU seals suit filtered-air operation from -20 to +70 °C, making it a durable workhorse for general industrial automation.
| Model | Airtac SCJ50 Standard Cylinder SCJ50X40-30LB |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø50 mm |
| Nominal stroke | 40 mm |
| Stroke adjustment | Up to 30 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. |
| ×40 | Nominal (maximum) stroke length in mm. |
| -30 | 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 30 mm rear screw adjustment lets technicians dial in the exact stroke end position during machine commissioning without changing the cylinder or adding external hard stops.
Quickly adapt the stroke to different product sizes on a packaging line. The LB foot mount provides stable, rigid support on the machine frame for consistent push forces.
Over time, tooling or gripper fingers can wear. The adjustable stroke end compensates for this drift, maintaining precise positioning without reprogramming the PLC.
Choose this 50 mm bore when your application needs roughly 1000 N of push force at standard plant pressure; stepping down to a 40 mm bore would cut that to 628 N, while moving up to 63 mm nearly doubles it to 1559 N. The 30 mm adjust range is ideal for commissioning trials or format changeovers where the stroke end must be dialled in on the machine without swapping the cylinder.
For replacement, match the bore (50 mm), nominal stroke (40 mm), adjust range (-30), and port thread (PT). This LB configuration uses the F-SC50LB foot bracket; if your original has a magnet, order the -S variant. For strokes of 300 mm or longer, consider an external guide rail to protect the 20 mm rod from side-load deflection.
Adjustable-stroke checklist
At 0.5 MPa air pressure, it generates 982 N of push force and 825 N on the pull stroke. At the maximum operating pressure of 1.0 MPa, the push force reaches 1767 N. Note that the adjusting screw sets the stroke end position and does not alter the cylinder's output force.
Yes, provided the bore (50 mm), nominal stroke (40 mm), and port thread (PT1/4) match. The SCJ body is slightly longer to house the adjusting mechanism, so check the 194 mm body length A against your available space. The LB foot mount must also match your existing bracket pattern.
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