Airtac SEJ Adjustable Cylinder SEJ40X125-30S
The AirTAC Airtac SEJ Adjustable Cylinder SEJ40X125-30S is a genuine double-acting ISO 15552 double-rod cylinder with a mechanically ADJUSTABLE stroke: a back-rod stop screw lets you fine-tune the retract end over a 30mm window, so this Ø40mm unit covers an effective stroke of 95–125mm without changing cylinders. Force is equal in both directions.
- BoreØ40 mm
- Nominal stroke125 mm
- Adjust window30 mm
- Effective stroke95–125 mm
- Port sizePT1/4
- CushionAdjustable, 30 mm
- No minimum order. A single piece can be ordered.
- Ready in 3–5 business days. That is the time we take to process the order and hand it to the carrier. Transit time after that depends on the destination.
About the Airtac SEJ Adjustable Cylinder SEJ40X125-30S
The AirTAC SEJ40X125-30S is a double-acting, double-rod ISO 15552 profile cylinder featuring a 30mm adjustable stroke window. A rod exits both ends, yielding identical annulus areas so output force is equal in both directions at 528 N each way at 0.5 MPa. You can dial the retract end from 95mm up to 125mm to perfectly match a machine stop.
The rear rod houses a mechanical stop screw for fine end-position tuning during commissioning. You lock it after setting your exact travel. This extruded aluminum barrel profile cylinder includes a -S magnet for CMSE reed or DMSE electronic sensors, PT1/4 ports, and field-adjustable air cushions at both ends for end-of-stroke deceleration.
Airtac SEJ Adjustable Cylinder SEJ40X125-30S Technical Specifications
| Model | Airtac SEJ Adjustable Cylinder SEJ40X125-30S |
|---|---|
| Series | SEJ ISO 15552 adjustable-stroke cylinder |
| Bore size | Ø40 mm |
| Nominal stroke | 125 mm |
| Adjustment window | 30 mm (95–125 mm) |
| Configuration | Double rod, double acting |
| Port size | PT1/4 |
| Rod thread | M12×1.25 |
|---|---|
| Operating pressure | 0.15 – 1.0 MPa |
| Proof pressure | 1.5 MPa |
| Temperature | -20 to +70 °C (0–150 °C with FKM seals) |
| Speed range | 30 – 800 mm/s |
| Cushion | Adjustable, 30 mm |
Specifications follow the official AirTAC SEJ datasheet and ISO 15552 / VDMA 24562 dimensions. The adjustment screw shortens the retract end only; do not exceed the 30mm window. Port options: PT (standard) / G (BSPP).
Theoretical Output Force (Ø40mm)
| Pressure | Force (both directions) |
|---|---|
| 0.5 MPa | 528 N |
| 0.7 MPa | 739 N |
| Max (@1.0 MPa) | 108 kgf |
A rod exits both ends, so extend and retract force are identical. Actual usable force is lower than theoretical; size with a safety margin.
Model Code: Airtac SEJ Adjustable Cylinder SEJ40X125-30S
| SEJ | ISO 15552 double-rod double-acting cylinder with adjustable stroke. |
|---|---|
| 40 | Bore size in mm. |
| ×125 | Nominal stroke length in mm. |
| -30 | Adjustment stroke window in mm (options: 10/20/30/40/50/75/100). |
| -S | Optional built-in magnet for CMSE / DMSE sensor sensing. |
Rod material: carbon steel (blank) / SUS420J2 (A) / SUS304 (B). Seals: TPU (blank) / FKM high-temp (H) / NBR (N). Thread: PT (blank) / G. Mounting (SEJ): Basic, LB, FA, TC, FTC, TCM1, TCM2. Related: SED (double rod, fixed stroke), SE (single rod).
Where the Airtac SEJ Adjustable Cylinder SEJ40X125-30S Is Used
Packaging Flap Folding
Dial the 95-125mm retract stroke to perfectly fold varying cardboard carton heights, utilizing the 528 N both-way force for consistent creasing.
Assembly Press Tunning
Fine-tune the exact pressing depth during machine commissioning using the back-rod stop screw, locking the 739 N @0.7 MPa force precisely where a bearing seats.
Component Changeover
Quickly adapt the end-stop position when switching between part families on a machining line, avoiding the need to physically swap cylinder hardware.
Is the Airtac SEJ Adjustable Cylinder SEJ40X125-30S the Right Cylinder?
Verify the 30mm adjustment window covers your required end-position range. Stepping down to the 32mm bore drops the both-way force to 345 N at 0.5 MPa, while moving up to the 50mm bore increases it to 825 N. If you do not need variable end-position tuning, a fixed-stroke SED cylinder is sufficient. For a drop-in ISO 15552 replacement, match the 40mm bore, 125mm nominal stroke, PT1/4 port, and mounting set (Basic, FA, LB, TC, FTC, TCM1, TCM2). The adjustable air cushion decelerates the load near stroke end but is not a lock; this plain SEJ does not hold position on air loss, so use an external rod lock for fail-safe holding.
Quick checklist
- ✓ Need on-machine stroke fine-tuning?
- ✓ Adjustment window (30mm) covers your range
- ✓ Equal force both directions OK
- ✓ Port/thread type (PT/G)
- ✓ Magnet (-S) for CMSE/DMSE 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 stop screw within the 30mm window; lock it after adjusting.
- check Adjust end cushion screws for smooth stops.
- check Use correct mounting accessory (LB/FA/TC/FTC/TCM1/TCM2).
- check Installation by qualified personnel per AirTAC docs.
Airtac SEJ Adjustable Cylinder SEJ40X125-30S FAQ
A stop screw on the back rod lets you mechanically shorten the retract stroke by up to 30mm. The effective stroke range is 95-125mm. You dial in the exact end-position on the machine and lock the screw in place.
Because the rod exits both ends, the force is identical in both directions. It generates 528 N at 0.5 MPa, 739 N at 0.7 MPa, and a maximum of 108 kgf at 1.0 MPa.
Authorized Export Seller
Genuine AirTAC parts produced by AirTAC factory.
1-Year Warranty
Covers non-human-caused product damage.
Fast Dispatch
Standard models are processed and dispatched in 3-5 business days.
Fast Reply
Most inquiries answered within 7-8 hours.
Related AirTAC SEJ Cylinders
Request a Quote for Airtac SEJ Adjustable Cylinder SEJ40X125-30S
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.