The AirTAC Airtac SCJ40 Standard Cylinder SCJ40X125-50S is a genuine double-acting SINGLE-ROD air cylinder with a rear-cap ADJUSTING SCREW: the stroke end is field-adjustable within a 50 mm range without swapping the cylinder. Ø40mm bore, 125mm nominal stroke, PT1/4 ports and adjustable end cushioning.
The SCJ40X125-50S is a 40 mm bore, single-rod double-acting cylinder offering a 125 mm nominal stroke with a 50 mm rear-end adjustment range. Its 16 mm piston rod delivers 628 N of push force at 0.5 MPa, making it a practical choice for applications needing on-machine stroke fine-tuning without swapping the cylinder.
A built-in magnet (suffix -S) allows direct mounting of CMSG/DMSG/EMSG sensors for reliable end-of-stroke detection. The cylinder body length A(SCJ) is 185 mm, and it features an adjustable air cushion for smooth deceleration. This model uses PT1/4 ports and an M12x1.25 rod thread.
| Model | Airtac SCJ40 Standard Cylinder SCJ40X125-50S |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø40 mm |
| Nominal stroke | 125 mm |
| Stroke adjustment | Up to 50 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. |
| -50 | 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 50 mm adjustment screw lets technicians precisely set the end-stop during machine setup, eliminating the need for external hard stops and reducing commissioning time.
Quickly adjust the stroke end for different product sizes on packaging or sorting lines. The built-in magnet enables sensor-based position confirmation for each new format.
In clamping or pressing fixtures, the adjustable stroke can be extended over time to compensate for tooling or pad wear, maintaining consistent contact without mechanical shims.
Choose this 40 mm bore for push forces around 628 N at 0.5 MPa. If you need more force, the 50 mm bore provides 982 N of push force. For less force in a smaller footprint, the 32 mm bore offers 402 N. The SCJ is the right pick when you need to dial in the stroke end position during commissioning or changeovers; if a fixed stroke is sufficient, the standard SC series is a more economical alternative.
This unit replaces any AirTAC SCJ40X125-50S with a PT port, basic mount, and magnet. For strokes of 300 mm or more, consider an external guide or a guided cylinder to protect the rod from side-load bending.
Adjustable-stroke checklist
At 0.5 MPa, the push force is 628 N and the pull force is 528 N. The push force is higher because the single rod reduces the effective piston area on the return stroke. The maximum operating push force at 0.9 MPa is 1130 N.
A rear-cap screw shortens the stroke end by up to 50 mm from the 125 mm nominal maximum. This is ideal for applications where the exact stroke length must be dialed in on the machine, such as during trials or format changes. Choose a fixed-stroke SC cylinder if your stroke requirement is final and will not change.
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