This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X280S, 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 SI125X280S
The AirTAC SI125 Standard Cylinder SI125X280S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 280mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X280S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke280 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X280S
- 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 SI125X280S
The AirTAC SI125X280S is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 280mm stroke. Delivering 6136 N push force at 0.5 MPa through a G1/2 port, it is replaced by the SAI125X280S. This direct successor shares the exact ISO 15552 mounting interface, bore, stroke, output force and port size, fitting existing fixtures perfectly.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. For applications needing load holding, the SAI family introduces SAIL and BSAI lock variants the SI lacked. This magnet-equipped -S model supports legacy CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X280S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X280S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X280S |
| Bore size | Ø125 mm |
| Stroke | 280 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 SAI125X280S 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 SAI125X280S 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 SI125X280S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×280 | 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 SI125X280S Is Used
Heavy Press Operations
Drives robust clamping and pressing fixtures requiring substantial thrust, utilizing the 6136 N push force at 0.5 MPa to form or secure heavy components.
Pallet Handling
Actuates large diverters and lifting gates in high-capacity distribution hubs, where the 313 kg vertical lift capacity easily manages heavy palletized goods.
Automated Assembly
Shifts heavy tooling platens and industrial actuators along the 280mm stroke, relying on the adjustable 40mm air cushions to decelerate substantial moving masses.
Replacing the Airtac SI125 Standard Cylinder SI125X280S with the SAI125X280S
To replace the SI125X280S, order the SAI125X280S. Verify your ISO 15552 mounting interface, 125mm bore, 280mm stroke, G1/2 port (PT/G/NPT thread), and mounting accessory. The -S suffix means a piston magnet for CS1-B/DS1-B switches is present. For sizing, the 125mm bore yields 6136 N push at 0.5 MPa; if less force is needed, an 80mm bore gives 2513 N, while a 160mm bore offers 10053 N. Note that a plain cylinder drifts on air loss—the cushion only decelerates. For held loads, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. At 280mm stroke, ensure guide alignment to prevent rod bending and side-load wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X280S
- ✓ 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 SI125X280S FAQ
Yes, the AirTAC SI125X280S is discontinued. The direct replacement is the SAI125X280S. It is dimensionally interchangeable per ISO 15552, matching the 125mm bore, 280mm stroke, output force, G1/2 port, and mounting interface for a seamless fixture upgrade.
The 125mm bore features a G1/2 air port and 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 SAI125X280S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X280S replacement — usually within 7-8 hours.