Airtac SAIJ125 Adjustable Cylinder SAIJ125X550-50S
The AirTAC Airtac SAIJ125 Adjustable Cylinder SAIJ125X550-50S is a genuine double-acting ISO 15552 profile-barrel air cylinder with a Ø125mm bore and 550mm 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
- Stroke550 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2
- CushionAdjustable, 40 mm
About the Airtac SAIJ125 Adjustable Cylinder SAIJ125X550-50S
The AirTAC SAIJ125X550-50-S is a double-acting, single-rod ISO 15552 profile cylinder equipped with a rear stroke adjuster. It delivers 6136N of push force at 0.5MPa and features a 500 to 550mm usable travel window, letting you dial back the nominal 550mm stroke by up to 50mm during commissioning. This built-in adjustability eliminates the need to swap cylinders or bolt on external stops when tuning end positions.
The extruded aluminum barrel includes sensor grooves on both sides, and this -S variant includes a magnet for use with AirTAC CMSE reed and DMSE electronic solid-state sensors. It uses a standard carbon steel piston rod with a PT tapered port thread. The rear adjuster acts purely as a mechanical travel stop to fine-tune deceleration alongside the variable air cushions, and it will not hold a load without live air pressure.
Airtac SAIJ125 Adjustable Cylinder SAIJ125X550-50S Technical Specifications
| Model | Airtac SAIJ125 Adjustable Cylinder SAIJ125X550-50S |
|---|---|
| Series | SAI ISO 15552 profile cylinder |
| Bore size | Ø125 mm |
| Stroke | 550 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 SAIJ125X550-50S
| SAI | ISO 15552 profile-barrel cylinder series. |
|---|---|
| 125 | Bore size in mm. |
| ×550 | 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 SAIJ125X550-50S Is Used
Product Changeover Tuning
Dial in the 500-550mm travel window during line changeovers to accommodate different product lengths without swapping out the entire actuator.
Commissioning End-Position Setup
Fine-tune the retract stroke by up to 50mm at machine commissioning, using the rear stopper to set exact deceleration without adding external mechanical stops.
Heavy Assembly Pressing
Leverage the 6136N push force at 0.5MPa for heavy-duty assembly operations while retaining the flexibility to adjust the pressing depth on the fly.
Is the Airtac SAIJ125 Adjustable Cylinder SAIJ125X550-50S the Right Cylinder?
Choose this 125mm bore cylinder when an application requires high force (6136N push at 0.5MPa) alongside variable end-stop positioning. If you need less force, stepping down to an 80mm bore yields 2513N of push force at 0.5MPa, whereas a 160mm bore offers 10053N for heavier loads. The adjustable stroke is ideal for machine setups requiring product-size changeovers without mechanical rebuilds. Because the 550mm stroke is long, an external guide is recommended to prevent excessive side-loading on the rod.
For an exact ISO 15552 replacement match, verify a 125mm bore, 550mm stroke, 50mm adjustment range, PT port thread, and the -S magnet option. The SAIJ mounting set includes Basic, FA, LB, TC, FTC, TCM1, and TCM2, omitting the FB, CA, CB, and CR mounts. If your process requires true load-holding without live air pressure, use an SAIL pneumatic lock or BSAI clamp-lock cylinder instead of relying on the rear stopper.
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 SAIJ125X550-50S FAQ
The rear adjusting screw acts as a mechanical stopper that lets you shorten the effective stroke by up to 50mm, providing a usable travel window of 500 to 550mm. It works with the variable air cushions to set deceleration, but it is not a lock and cannot hold a load without continuous air pressure.
At 0.5MPa, this 125mm bore cylinder provides 6136N of push force and 5734N of pull force. If operated at 0.7MPa, the push force increases to 8590N.
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