The AirTAC Airtac SCJ250 Standard Cylinder SCJ250X400-75S is a genuine double-acting SINGLE-ROD air cylinder with a rear-cap ADJUSTING SCREW: the stroke end is field-adjustable within a 75 mm range without swapping the cylinder. Ø250mm bore, 400mm nominal stroke, PT1" ports and adjustable end cushioning.
The SCJ250X400-75S is a heavy-duty double-acting single-rod cylinder engineered for applications where the stroke end position must be fine-tuned on the machine. Its rear-cap adjusting screw provides a 75 mm field-adjustable range, allowing operators to dial in the exact stroke end without removing the cylinder or adding external hard stops. With a 50 mm diameter piston rod and a body length A of 409 mm, this tie-rod cylinder delivers a substantial 24544 N of push force at 0.5 MPa.
Built for large-scale industrial tasks, the 250 mm bore generates a theoretical maximum force of 5006 kgf at 1.0 MPa. The integrated magnet (denoted by the -S suffix) allows for direct mounting of CMSG, DMSG, or EMSG sensors on the barrel for reliable, non-contact position feedback. The cylinder operates on filtered air at 0.15-1.0 MPa and features an adjustable pneumatic cushion to decelerate the massive piston smoothly, with a speed range of 30-500 mm/s typical for this ISO 6430 class cylinder.
| Model | Airtac SCJ250 Standard Cylinder SCJ250X400-75S |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder (ISO 6430 class) |
| Bore size | Ø250 mm |
| Nominal stroke | 400 mm |
| Stroke adjustment | Up to 75 mm (rear adjusting screw) |
| Acting type | Double acting (single rod) |
| Port size | PT1" |
| Rod thread | M42×2 |
| 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 – 500 mm/s |
| Cushion | Adjustable, 40 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 | 24544 N | 23562 N |
| 0.7 MPa | 34361 N | — |
| Max (@1.0 MPa) | 5006 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. |
|---|---|
| 250 | Bore size in mm. |
| ×400 | Nominal (maximum) stroke length in mm. |
| -75 | 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.
In a large hydraulic-style pneumatic press, the 75 mm adjustment screw lets operators precisely dial in the final press-fit depth for different part batches without changing tooling, using the cylinder's 24544 N push force.
Controls a diverter gate on a mining or aggregate conveyor. The adjustable stroke allows for fine-tuning the gate's open position to match different chute sizes, compensating for wear on the gate linkage over time.
Positions a heavy log fence in a sawmill. The 75 mm adjustment range enables quick changeover between different cutting patterns, and the built-in magnet provides sensor feedback to the PLC to confirm the fence is in the correct position.
Select the SCJ250X400-75S when you need the raw force of a 250 mm bore combined with the ability to trim the stroke end by up to 75 mm during commissioning or product changeovers. If your force requirement is slightly lower, stepping down to the 200 mm bore reduces push force to 15708 N at 0.5 MPa, which may allow for a smaller, lighter cylinder. For applications needing a fixed, non-adjustable stroke, the standard SC series is a more economical choice. This model is a direct replacement for an existing AirTAC SCJ cylinder with a 250 mm bore, 400 mm nominal stroke, 75 mm adjust range, PT ports, and a magnet. For this long 400 mm stroke, always evaluate the side load on the 50 mm rod; if the load is not perfectly guided, an external guide rail or a switch to a guided cylinder is strongly recommended to prevent rod bending and premature seal wear.
Adjustable-stroke checklist
At the standard 0.5 MPa operating pressure, it generates 24544 N of push force and 23562 N of pull force. The maximum push force at 0.9 MPa is 44178 N. The pull force is lower because the 50 mm piston rod reduces the effective piston area on the return stroke.
You can replace an existing AirTAC SCJ250 with a 400 mm stroke and 75 mm adjust range directly. The SCJ series is a tie-rod design, not an ISO 15552 profile cylinder, so it is not dimensionally interchangeable with those types. The -S suffix confirms this model includes a magnet for sensor mounting, and the port thread is standard PT.
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