This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX280S, 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 SI125AX280S
The AirTAC SI125 Standard Cylinder SI125AX280S 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 SAI125AX280S, 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 → SAI125AX280S
- 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 SI125AX280S
The AirTAC SI125AX280S is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore, 280mm stroke, and an SUS420J2 stainless steel rod. Delivering 6136N push force at 0.5MPa, it is directly replaced by the SAI125AX280S. This direct upgrade shares the exact ISO 15552 mounting interface, G1/2 port, and M27x2 rod thread, fitting existing fixtures seamlessly.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This -S model has a piston magnet for legacy CS1-B/DS1-B sensors. For high heat, Viton H seals raise the temperature range to 0-150C.
Airtac SI125 Standard Cylinder SI125AX280S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX280S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX280S |
| 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 SAI125AX280S 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 SAI125AX280S 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 SI125AX280S
| 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 SI125AX280S Is Used
Heavy-Duty Pressing
Ideal for applying high clamping forces in automated assembly lines, utilizing the 6136N push force at 0.5MPa to seat large bearings or form heavy components.
Pallet Handling
Drives robust lifting and positioning mechanisms in logistics conveyors, where the 313kg vertical lift capacity handles substantial packaged loads securely.
Stainless Rod Washdown
The SUS420J2 stainless piston rod variant excels in food processing or mildly corrosive environments where standard carbon steel rods would degrade.
Replacing the Airtac SI125 Standard Cylinder SI125AX280S with the SAI125AX280S
To replace the SI125AX280S, order the SAI125AX280S. Confirm the ISO 15552 mounting interface, the 125mm bore, 280mm stroke, G1/2 port, and your specific mounting accessory. The -S denotes a magnet for CS1-B/DS1-B switches; the SAI uses current AirTAC switches. The -A rod is SUS420J2 stainless steel, offering corrosion resistance over the standard carbon steel rod. Sizing both ways: a 100mm bore yields 3927N push at 0.5MPa, while a 160mm bore yields 10053N. Note that a plain cylinder drifts on air loss—the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants. At 280mm stroke, ensure guide alignment to prevent rod bending side-loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX280S
- ✓ 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 SI125AX280S FAQ
Yes, the AirTAC SI125AX280S is discontinued. The direct replacement is the SAI125AX280S. It shares the same ISO 15552 mounting interface, 125mm bore, 280mm stroke, output force, G1/2 port, and M27x2 rod thread, fitting existing fixtures perfectly.
This 125mm bore cylinder has a G1/2 air port. The thrust ratings are: 6136N push and 5734N pull at 0.5MPa; 8590N push at 0.7MPa; 11045N push at 0.9MPa; and a theoretical maximum force of 1251kgf at 1.0MPa. Operating speed is 30-500mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX280S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125AX280S replacement — usually within 7-8 hours.