Airtac SCJ40 Standard Cylinder SCJ40X250-20
The AirTAC Airtac SCJ40 Standard Cylinder SCJ40X250-20 is a genuine double-acting SINGLE-ROD air cylinder with a rear-cap ADJUSTING SCREW: the stroke end is field-adjustable within a 20 mm range without swapping the cylinder. Ø40mm bore, 250mm nominal stroke, PT1/4 ports and adjustable end cushioning.
- BoreØ40 mm
- Nominal stroke250 mm
- Stroke adjust-20 mm
- Port sizePT1/4
- Rod threadM12×1.25
- CushionAdjustable, 21 mm
About the Airtac SCJ40 Standard Cylinder SCJ40X250-20
The SCJ40X250-20 brings field-adjustable stroke control to a 40 mm bore double-acting cylinder, delivering 628 N of push force at 0.5 MPa. A rear-cap adjusting screw lets you shorten the stroke end by up to 20 mm without removing the cylinder, making it ideal for commissioning fine-tuning or accommodating small process changes on the fly.
This single-rod tie-rod cylinder uses a 16 mm diameter rod and PT1/4 ports, with a 21 mm air cushion at each end for smooth deceleration. Its body length A is 185 mm, and it operates reliably on filtered air from 0.15 to 1.0 MPa across a standard temperature range of -20 to +70 °C.
Airtac SCJ40 Standard Cylinder SCJ40X250-20 Technical Specifications
| Model | Airtac SCJ40 Standard Cylinder SCJ40X250-20 |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø40 mm |
| Nominal stroke | 250 mm |
| Stroke adjustment | Up to 20 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.
Theoretical Output Force (Ø40mm)
| 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.
Model Code: Airtac SCJ40 Standard Cylinder SCJ40X250-20
| SCJ | Adjustable-stroke tie-rod cylinder series. |
|---|---|
| 40 | Bore size in mm. |
| ×250 | Nominal (maximum) stroke length in mm. |
| -20 | 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.
Where the Airtac SCJ40 Standard Cylinder SCJ40X250-20 Is Used
Commissioning & Setup
Fine-tune the end position of a stopper or clamp during machine commissioning without swapping cylinders, using the 20 mm rear adjustment screw to dial in the exact stroke required.
Product Format Changeover
Quickly adjust the push-off stroke for different box sizes on a packaging line. The operator can shorten the stroke end by up to 20 mm to handle a new product format without mechanical rework.
Wear Compensation
Compensate for pad or tooling wear in a pressing or clamping station. The adjustable stroke end allows the operator to take up slack over time, maintaining consistent contact force without replacing the tooling.
Is the Airtac SCJ40 Standard Cylinder SCJ40X250-20 the Right Cylinder?
Choose this 40 mm bore when your application needs around 628 N of push force at standard plant pressure. If you require more force, stepping up to the 50 mm bore (SCJ50) provides 982 N of push at the same 0.5 MPa. For applications where the stroke never needs adjustment, the fixed-stroke SC40 series offers a simpler, more cost-effective alternative. When replacing an existing unit, match the 40 mm bore, 250 mm nominal stroke, 20 mm adjust range, PT port thread, and basic mounting style to ensure direct interchangeability.
Adjustable-stroke checklist
- ✓ Need to fine-tune stroke on the line?
- ✓ Nominal stroke + adjust range (-20)
- ✓ Required force at your working pressure
- ✓ Port/thread type (PT/NPT/G)
- ✓ Magnet (-S) for sensors?
Installation & Maintenance Notes
- check Use clean air filtered to 40µm or finer.
- check Keep within 0.15 – 1.0 MPa operating pressure.
- check Set the rear adjusting screw, then lock it before running.
- check Adjust end cushion screws for smooth stops.
- check Use SCJ mounting accessory (FA / LB / TC / TCM1).
- check Installation by qualified personnel per AirTAC docs.
Airtac SCJ40 Standard Cylinder SCJ40X250-20 FAQ
At 0.5 MPa, the push force is 628 N and the pull force is 528 N (the difference is due to the 16 mm rod area on the return side). At the maximum operating pressure of 0.9 MPa, the push force reaches 1130 N.
Yes, if you need the ability to fine-tune the stroke end. The SCJ40X250-20 has the same 40 mm bore and 250 mm maximum stroke as an SC40x250, but adds a rear adjusting screw that can shorten the stroke by up to 20 mm. Ensure the port thread (PT) and mounting style match your current setup.
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