Airtac SAIJ125 Adjustable Cylinder SAIJ125X400-40
The AirTAC Airtac SAIJ125 Adjustable Cylinder SAIJ125X400-40 is a genuine double-acting ISO 15552 profile-barrel air cylinder with a Ø125mm bore and 400mm stroke, G1/2 air ports and adjustable end cushioning. Its standardized mounting interface makes it a drop-in replacement for other ISO 15552 cylinders in automation lines.
- BoreØ125 mm
- Stroke400 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2
- CushionAdjustable, 40 mm
About the Airtac SAIJ125 Adjustable Cylinder SAIJ125X400-40
The AirTAC SAIJ125X400-40 is a double-acting, single-rod ISO 15552 profile cylinder equipped with a rear stroke adjuster. It provides a 400 mm nominal stroke that can be fine-tuned down by up to 40 mm, creating a usable travel window of 360-400 mm. Belonging to the 125 mm bore class, it delivers substantial thrust—generating 8590 N of push force at 0.7 MPa—making it suitable for heavy-duty positioning tasks.
This extruded aluminum profile cylinder features a PT tapered port thread, a 32 mm carbon steel piston rod with an M27x2 male thread, and variable air cushions at both ends. The rear adjusting screw acts purely as a mechanical stop to dial in the exact retract end-position during commissioning; it is not a locking device and will not hold a load without continuous live air pressure. For load-holding requirements without air, consider an external rod lock or related types like the SAIL or BSAI.
Airtac SAIJ125 Adjustable Cylinder SAIJ125X400-40 Technical Specifications
| Model | Airtac SAIJ125 Adjustable Cylinder SAIJ125X400-40 |
|---|---|
| Series | SAI ISO 15552 profile cylinder |
| Bore size | Ø125 mm |
| Stroke | 400 mm |
| Acting type | Double acting |
| Port size | G1/2 |
| Rod thread | M27×2 |
| 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 SAI series datasheet and ISO 15552 dimensions. Confirm against the product label before installation. Port options: G (BSPP) / NPT.
Theoretical Output Force (Ø125mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 6136 N | 5734 N |
| 0.7 MPa | 8590 N | — |
| Max (@1.0 MPa) | 1251 kgf | |
Actual usable force is lower than theoretical due to friction and back-pressure. Size with a safety margin.
Model Code: Airtac SAIJ125 Adjustable Cylinder SAIJ125X400-40
| SAI | ISO 15552 profile-barrel cylinder series. |
|---|---|
| 125 | Bore size in mm. |
| ×400 | Stroke length in mm. |
| -S | Optional built-in magnet for sensor position sensing. |
Related SAI-family variants: SAID (double rod), SAIJ (adjustable stroke), SAIL (with lock), SAIF (with valve), BSAI (enclasp / clamp-lock), and SAI-S with built-in magnet. Rod material: carbon steel (blank) / SUS420J2 (A) / SUS304 (B); seals: TPU (blank) / Viton H / NBR N.
Where the Airtac SAIJ125 Adjustable Cylinder SAIJ125X400-40 Is Used
Variable End-Stop Configuration
Dial in the exact retract position within the 360-400 mm window during machine setup, allowing rapid accommodation of different material thicknesses without changing the cylinder.
Heavy-Duty Forming Press
Leverage the 8590 N push force at 0.7 MPa to drive heavy forming tools, relying on the rear stopper to precisely set the bottom dead center for consistent part production.
Product Size Changeover
Quickly adjust the effective stroke on automated packaging lines when switching between different package dimensions, minimizing downtime and avoiding external stop hardware.
Is the Airtac SAIJ125 Adjustable Cylinder SAIJ125X400-40 the Right Cylinder?
Select this 125 mm bore model when an application demands high force alongside precise end-position tuning without swapping out the entire cylinder. If the 6136 N push force at 0.5 MPa exceeds your requirement, stepping down to a 100 mm bore yields 5497 N at 0.7 MPa. Conversely, if you need more power, the 160 mm bore provides 14074 N at 0.7 MPa. The adjustable 360-400 mm window is perfect for machines processing varying product sizes, allowing operators to change the end-stop quickly rather than installing external physical stops.
When specifying a replacement, ensure you match the 125 mm bore, 400 mm stroke, 40 mm adjustment range, PT port thread, and the required mounting style. SAIJ supports a specific subset of ISO 15552 mounts: Basic, FA, LB, TC, FTC, TCM1, and TCM2—omitting FB, CA, CB, and CR options. Because this unit features a 400 mm stroke, the extended length increases the risk of side-loading; ensure an external guide is used to prevent rod damage, despite the robust 32 mm carbon steel rod. The operating speed range for this bore size is 30-500 mm/s.
Quick checklist
- ✓ Required force at your working pressure
- ✓ Stroke and mounting space
- ✓ Port/thread type (PT/NPT/G)
- ✓ Magnet (-S) for sensors?
- ✓ Side load — consider a guided cylinder
Installation & Maintenance Notes
- check Use clean air filtered to 40µm or finer.
- check Keep within 0.15 – 1.0 MPa operating pressure.
- check Avoid side load on the piston rod.
- check Adjust end cushion screws for smooth stops.
- check Use correct mounting accessory (FA/FB/CA/CB/LB/TC).
- check Installation by qualified personnel per AirTAC docs.
Airtac SAIJ125 Adjustable Cylinder SAIJ125X400-40 FAQ
At 0.5 MPa it provides 6136 N of push force and 5734 N of pull force. At 0.7 MPa, the push force increases to 8590 N, and at 0.9 MPa it reaches 11045 N. The maximum rated force is 1251 kgf at 1.0 MPa.
The rear adjuster screw allows you to mechanically shorten the effective stroke by up to 40 mm from the nominal 400 mm, providing a usable travel window of 360-400 mm. This stopper only sets the end position for commissioning; it does not lock or hold the load without live air pressure.
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