The AirTAC Airtac SCJ40 Standard Cylinder SCJ40X250-40 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, 250mm nominal stroke, PT1/4 ports and adjustable end cushioning.
The SCJ40X250-40 is a double-acting, single-rod pneumatic cylinder with a field-adjustable stroke end, offering a 40 mm adjustment range on a 250 mm nominal stroke. The rear-cap screw lets you fine-tune the end position without changing the cylinder, delivering 628 N of push force at 0.5 MPa and 1130 N at 0.9 MPa.
This 40 mm bore tie-rod cylinder uses a 16 mm rod, PT1/4 ports, and an M12x1.25 rod thread. Its 21 mm air cushion decelerates the piston quietly, and the body length A(SCJ) is 185 mm. It is a genuine AirTAC unit built for repeatable commissioning and format-change tasks.
| Model | Airtac SCJ40 Standard Cylinder SCJ40X250-40 |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø40 mm |
| Nominal stroke | 250 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. |
| ×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.
The 40 mm adjust range lets technicians fine-tune the end stop during machine commissioning without swapping cylinders or machining external hard stops.
Adjust the stroke end in seconds when switching between product sizes on a packaging or assembly line, reducing downtime between batches.
As gripper pads or tooling wear, the rear adjusting screw can be turned to recover the precise end position, maintaining consistent part engagement.
Choose this SCJ when you need to dial in the stroke end on a 40 mm bore machine axis, such as during product changeovers or wear compensation. If 628 N push is marginal, stepping up to a 50 mm bore SCJ provides 982 N at the same pressure; if space is tight, the 32 mm bore delivers 402 N. For a fixed stroke without the rear screw, the standard SC40X250 is the direct alternative.
A direct replacement must match the 40 mm bore, 250 mm nominal stroke, 40 mm adjust range, PT1/4 ports, and basic mounting. At this 250 mm stroke, ensure the rod is guided externally if side loads are present, or consider a guided cylinder to prevent rod bending.
Adjustable-stroke checklist
At 0.5 MPa, the push force is 628 N and the pull force is 528 N (single rod). At the maximum operating pressure of 0.9 MPa, push force reaches 1130 N. The theoretical maximum at 1.0 MPa is 128 kgf.
A rear-cap adjusting screw lets you shorten the stroke end by up to 40 mm from the 250 mm nominal maximum. Pick the SCJ when you need to fine-tune the end position on the machine, such as during setup or format changes. Choose a fixed-stroke SC if the stroke never needs field adjustment and you want a simpler, lower-cost cylinder.
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