The AirTAC Airtac SCJ80 Standard Cylinder SCJ80X125-40S 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. Ø80mm bore, 125mm nominal stroke, PT3/8 ports and adjustable end cushioning.
The SCJ80X125-40S delivers 2513 N of push force at 0.5 MPa from an 80 mm bore, with a field-adjustable stroke end that can be shortened by up to 40 mm via the rear-cap screw. This model includes a built-in magnet, allowing CMSG/DMSG/EMSG sensors to be clamped directly onto the tie-rod barrel for reliable, non-contact position sensing.
With a 25 mm piston rod, PT3/8 ports, and a 28 mm air cushion, the cylinder handles speeds from 30 to 800 mm/s. The adjustable feature is ideal for commissioning fine-tuning, format changeovers, or compensating for tooling wear without swapping the cylinder or adding external hard stops.
| Model | Airtac SCJ80 Standard Cylinder SCJ80X125-40S |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø80 mm |
| Nominal stroke | 125 mm |
| Stroke adjustment | Up to 40 mm (rear adjusting screw) |
| Acting type | Double acting (single rod) |
| Port size | PT3/8 |
| Rod thread | M20×1.5 |
| 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 | 2513 N | 2268 N |
| 0.7 MPa | 3519 N | — |
| Max (@1.0 MPa) | 513 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. |
|---|---|
| 80 | Bore size in mm. |
| ×125 | 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.
Field engineers adjust the 40 mm stroke-end range to dial in the exact stop position during machine commissioning, eliminating the need to swap cylinders for minor dimensional tweaks.
On packaging lines, operators quickly re-set the stroke end to accommodate different box or product heights, reducing downtime between batches without mechanical modifications.
In clamping or pressing fixtures, the rear screw is periodically adjusted to take up slack from pad or tooling wear, maintaining consistent contact force and cycle quality over time.
Step up to the 100 mm bore SCJ for 3927 N push at 0.5 MPa if this model's 2513 N is marginal; step down to the 63 mm bore for 1559 N when space and air consumption must be minimized. For applications where the stroke length is permanently fixed, a standard SC fixed-stroke cylinder is a simpler, lower-cost alternative. If the 125 mm stroke creates a side-loading risk, pair the cylinder with an external guide rail or consider a guided cylinder.
To replace an existing SCJ80X125-40S, match the 80 mm bore, 125 mm nominal stroke, 40 mm adjustment range, PT port thread, basic mounting, and the -S magnet option. The mounting accessory code for a centre trunnion, if needed later, is F-SC80TC.
Adjustable-stroke checklist
At 0.5 MPa, the push force is 2513 N and the pull force is 2268 N. At the maximum operating pressure of 1.0 MPa, the theoretical push force reaches 5026 N. The push force is always greater than the pull force because this is a single-rod cylinder.
No. Like all standard pneumatic cylinders, the SCJ80X125-40S will drift or drop if air pressure is lost or the directional valve is centred. The adjustable screw only sets the stroke end position and the air cushion only decelerates the piston; neither acts as a lock. If load holding is required, add a pilot-operated check valve or an external rod brake.
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