This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X225STC, with the same bore, stroke, output force, port and mounting, so it fits the same application. The SAI replacement keeps the same ISO 15552 mounting interface, bore, stroke, output force and accessories, so it drops straight into existing fixtures. It is the current-production version of this cylinder with an upgraded piston seal.
Airtac SI125 Standard Cylinder SI125X225STC
The AirTAC SI125 Standard Cylinder SI125X225STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 225mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X225STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke225 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X225STC
- 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 SI125 Standard Cylinder SI125X225STC
The AirTAC SI125X225STC is a discontinued double-acting ISO 15552 profile cylinder featuring a 125 mm bore and a 225 mm non-standard stroke. It delivers a push force of 6136 N at 0.5 MPa and uses a G1/2 air port with a TC trunnion mount. AirTAC replaced this legacy unit with the SAI125X225STC, a direct replacement retaining the exact ISO 15552 mounting interface, bore, stroke, output force, port size and mounting accessories.
The SAI upgrade introduces an advanced piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. For load-holding, note that a standard cylinder drifts without live air; the cushion only decelerates. Use an external rod lock or pilot check valve, or explore the SAI family's new SAIL air-released lock and BSAI clamp-lock variants.
Airtac SI125 Standard Cylinder SI125X225STC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X225STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X225STC |
| Bore size | Ø125 mm |
| Stroke | 225 mm |
| Acting type | Double acting |
| Port size | G1/2 |
| Rod thread | M27×2.0 |
| 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 standard stroke | Up to 1500 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI125X225STC carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / 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 | |
The SAI125X225STC produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI125 Standard Cylinder SI125X225STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×225 | Stroke length in mm. |
| -S | Optional built-in magnet for sensor position sensing. |
Legacy SI-family variants: SID (double rod), SIJ (adjustable stroke) — each maps to its SAI equivalent (SID→SAID, SIJ→SAIJ). Rod material: carbon steel (blank) / SUS420J2 (A) / SUS304 (B).
Where the Airtac SI125 Standard Cylinder SI125X225STC Is Used
Heavy Press Clamping
Secures large steel plates in a hydraulic press fixture, utilizing the 6136 N push force at 0.5 MPa to hold components firmly during stamping operations.
Pallet Lift Gates
Actuates heavy-duty diverter gates on automated pallet conveyors, where the TC trunnion mount absorbs lateral stress during 225 mm travel.
Injection Mold Ejection
Drives the ejection plate on large injection molding machines, requiring the 125 mm bore's robust 5734 N pull force to extract dense plastic parts.
Replacing the Airtac SI125 Standard Cylinder SI125X225STC with the SAI125X225STC
To replace the SI125X225STC, order the SAI125X225STC. Verify the ISO 15552 TC trunnion interface, 125 mm bore, 225 mm stroke, G1/2 port (PT/G/NPT thread options), and the -S magnet for CS1-B/DS1-B sensors (the SAI uses current AirTAC switches). Because 225 mm is a non-standard stroke, confirm the exact rod length. Sizing both ways: a 100 mm bore yields 3927 N push at 0.5 MPa, while a 160 mm bore yields 10053 N. For this 225 mm stroke, ensure external guides to prevent rod-bending side loads. If the load must be held without air pressure, do not rely on the cushion; specify an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X225STC
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI125 Standard Cylinder SI125X225STC FAQ
Yes, the SI125X225STC is discontinued. The direct replacement is the AirTAC SAI125X225STC. It is dimensionally interchangeable per ISO 15552, matching the 125 mm bore, 225 mm stroke, G1/2 port, TC trunnion mount, and output force exactly.
This 125 mm bore cylinder features a G1/2 air port, a 32 mm rod, and an M27x2 rod thread. Force ratings are: 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N push at 0.9 MPa, and a theoretical maximum of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X225STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X225STC replacement — usually within 7-8 hours.