The AirTAC Airtac SCJ40 Standard Cylinder SCJ40X300-40 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, 300mm nominal stroke, PT1/4 ports and adjustable end cushioning.
The SCJ40X300-40 is a double-acting, single-rod pneumatic cylinder with a field-adjustable stroke, offering a 40 mm adjustment range via a rear-cap screw. This 40 mm bore actuator delivers 628 N of push force at 0.5 MPa and 1130 N at 0.9 MPa, making it a robust choice for mid-range automation tasks where the final stop position needs fine-tuning during commissioning or changeovers.
Its 16 mm diameter piston rod and PT1/4 ports are standard for the SCJ40 family, while the 21 mm air cushion decelerates the piston smoothly at stroke end. The body length A is 185 mm plus the nominal stroke, providing a compact yet powerful package for format-dependent machinery.
| Model | Airtac SCJ40 Standard Cylinder SCJ40X300-40 |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø40 mm |
| Nominal stroke | 300 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. |
| ×300 | 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 adjustment screw lets operators quickly reset the stroke end for different product sizes on packaging or labeling lines, eliminating the need for mechanical hard stops.
During machine build and testing, engineers can incrementally adjust the 300 mm nominal stroke by up to 40 mm to perfectly synchronize the actuator's end position with other tooling.
In long-running clamping or pressing fixtures, the adjustable stroke can be tweaked over time to compensate for pad or tool wear, maintaining consistent contact force without reprogramming.
Choose the SCJ40X300-40 when you need to dial in a precise stroke end without swapping cylinders. If 628 N of push force is insufficient, stepping up to the SCJ50 bore provides 982 N at the same 0.5 MPa pressure. For applications where the stroke is fixed and never needs adjustment, the standard SC40X300 fixed-stroke cylinder is a more economical alternative. This model is a direct replacement for any AirTAC SCJ40X300-40 with PT ports and basic mounting. For strokes of 300 mm or more, ensure the rod is not subjected to high side loads; if lateral forces are present, add an external linear guide or consider a guided cylinder to prevent rod bending.
Adjustable-stroke checklist
The rear cap houses an adjusting screw that limits the piston's retraction stroke. By turning this screw, you can shorten the effective stroke end by up to 40 mm from the nominal 300 mm maximum. It only adjusts the stroke end position, not the cylinder's force or speed.
At 0.5 MPa, the push force is 628 N and the pull force is 528 N (reduced due to the 16 mm rod area). The maximum push force at the 0.9 MPa operating limit is 1130 N. The theoretical force at 1.0 MPa is 128 kgf.
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