This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X900S, 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 SI125X900S
The AirTAC SI125 Standard Cylinder SI125X900S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 900mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X900S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke900 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X900S
- 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 SI125X900S
The AirTAC SI125X900S is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 900mm stroke. It delivers 6136N push force at 0.5MPa via a G1/2 port. The direct replacement is the SAI125X900S, retaining identical mounting, output, and dimensions.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life. The SAI family adds SAIL and BSAI lock variants the SI lacked. Your -S magnet supports CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X900S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X900S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X900S |
| Bore size | Ø125 mm |
| Stroke | 900 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 SAI125X900S 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 SAI125X900S 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 SI125X900S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×900 | 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 SI125X900S Is Used
Heavy Material Lifts
Raises heavy platens or lifting gates in automated plants, utilizing the 6136N push force at 0.5 MPa to move substantial masses over the 900mm travel distance.
Large Press Ejection
Ejects bulky formed parts from large industrial presses, requiring the long 900mm extraction stroke and robust 125mm bore thrust capacity.
Pallet Positioning
Shifts or indexes loaded pallets along conveyor lines in distribution hubs, taking advantage of the high force class and extended reach.
Replacing the Airtac SI125 Standard Cylinder SI125X900S with the SAI125X900S
To replace the SI125X900S, order the SAI125X900S. Verify the ISO 15552 mounting interface, 125mm bore, 900mm stroke, G1/2 port (PT/G/NPT), and mounting accessory. The -S suffix means a magnet for CS1-B/DS1-B switches; SAI uses current AirTAC switches. Neighbouring bores: 100mm gives 3927N [email protected], 160mm gives 10053N. A plain cylinder drifts on air loss; for load holding use an external rod lock or pilot check valve. With a 900mm stroke, use external guides to prevent rod bending and side loads. Speed is 30-500mm/s.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X900S
- ✓ 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 SI125X900S FAQ
Yes, the SI125X900S is discontinued. The direct replacement is the SAI125X900S. It is dimensionally interchangeable per ISO 15552, keeping the same 125mm bore, 900mm stroke, G1/2 port, and mounting interface, so it drops directly into existing fixtures.
The G1/2 port is fixed by the 125mm bore. Force ratings are: 6136N push and 5734N pull at 0.5 MPa, 8590N push at 0.7 MPa, 11045N push at 0.9 MPa, and a theoretical max of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X900S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X900S replacement — usually within 7-8 hours.