The AirTAC Airtac SCJ250 Standard Cylinder SCJ250X250-40S 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. Ø250mm bore, 250mm nominal stroke, PT1" ports and adjustable end cushioning.
The SCJ250X250-40S is a heavy-duty double-acting, single-rod cylinder from AirTAC's adjustable-stroke series, delivering a substantial 24544 N of push force at just 0.5 MPa. Its defining feature is a rear-cap adjusting screw that provides up to 40 mm of stroke-end reduction, allowing engineers to fine-tune the piston stop position in situ without disassembling the cylinder or adding external hard stops. The 50 mm diameter piston rod and PT1" port ensure robust flow and mechanical strength for demanding applications.
This ISO 6430 class tie-rod cylinder is equipped with a built-in magnet, enabling direct mounting of CMSG, DMSG, or EMSG reed and solid-state sensors along the barrel for precise, contactless position feedback. With a 40 mm adjustable cushion and a body length A of 409 mm, it is designed for controlled deceleration of large inertial loads. The operating pressure ranges from 0.15 to 1.0 MPa, with a proof pressure of 1.5 MPa, confirming its suitability for high-force industrial tasks.
| Model | Airtac SCJ250 Standard Cylinder SCJ250X250-40S |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder (ISO 6430 class) |
| Bore size | Ø250 mm |
| Nominal stroke | 250 mm |
| Stroke adjustment | Up to 40 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. |
| ×250 | 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.
Fine-tune the final pressing depth in a 250-ton forming press. The 40 mm adjustment screw allows operators to dial in the exact bottom-dead-center position for different die sets or material thicknesses, compensating for tooling wear without replacing the cylinder.
Control the stroke end of a large-diameter knife gate valve handling slurry. The adjustable stroke ensures the gate fully seats against the seal every cycle, and the built-in magnet provides open/closed confirmation via DMSG sensors to the PLC.
Set the retract stop for a log fence on a high-production sawmill carriage. The SCJ250X250-40S allows quick, tool-free stroke-end changes to accommodate different log diameters, maximizing yield and reducing setup time between batches.
Select the SCJ250 bore when your application demands forces in the 24544 N (push at 0.5 MPa) class. If your force requirement is lower, stepping down to the 200 mm bore provides 15708 N of push force, offering a more compact and energy-efficient solution. For applications where the stroke length is fixed and will never need field adjustment, the standard SC250 fixed-stroke cylinder is a simpler, more cost-effective alternative. For direct replacement, match this model exactly: an AirTAC SCJ adjustable-stroke cylinder with a 250 mm bore, 250 mm nominal stroke, a 40 mm adjustment range, PT port thread, and a built-in magnet. For strokes of 300 mm or more, carefully evaluate side-loading and rod bending; an external guide rail or a switch to a guided cylinder is recommended to protect the rod and seals from premature wear.
Adjustable-stroke checklist
At 0.7 MPa operating pressure, the theoretical push force is 34361 N, and the pull force on the retract stroke is 23562 N. The pull force is lower because the 50 mm piston rod reduces the effective piston area on the rod side. These values are for a dynamic application; static holding force is higher but requires a pilot-operated check valve if pressure must be maintained without the pump running.
You can replace a fixed-stroke AirTAC SC250 or another brand's 250 mm bore cylinder with the SCJ250X250-40S only if you need the 40 mm stroke-end adjustment feature and the mounting dimensions are compatible. This is a tie-rod cylinder, not an ISO 15552 profile cylinder, so check the body length A (409 mm) and mounting hole patterns. The port is PT1", and the rod thread is M42x2. The built-in magnet (-S suffix) is an added feature for sensor mounting.
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