This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X900, 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 SI125X900
The AirTAC SI125 Standard Cylinder SI125X900 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 SAI125X900, 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 → SAI125X900
- 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 SI125X900
The AirTAC SI125X900 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 900 mm stroke, delivering 6136 N push force at 0.5 MPa. AirTAC replaced it with the SAI125X900, a direct upgrade sharing the exact ISO 15552 mounting interface, G1/2 port, and M27x2 rod thread.
The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This non-magnet SKU cannot take a sensor. If high heat is a factor, Viton H seals raise the operating range to 150 C.
Airtac SI125 Standard Cylinder SI125X900 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X900 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X900 |
| 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 SAI125X900 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 SAI125X900 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 SI125X900
| 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 SI125X900 Is Used
Heavy Press Demolding
Generates 6136 N at 0.5 MPa to break large injection-molded parts free from deep tooling cavities over the 900 mm extraction travel.
Pallet Transfer Pusher
Moves heavy loaded pallets along a transfer line, utilizing the long 900 mm stroke to span wide conveyor gaps without intermediate actuators.
Replacing the Airtac SI125 Standard Cylinder SI125X900 with the SAI125X900
To replace the SI125X900, order the SAI125X900 and confirm the ISO 15552 mounting accessory (LB, FA, TC, etc.) and G1/2 port match your fixture. This 900 mm stroke demands external guide rails to prevent rod bending and side-load wear. If sizing up or down, neighboring bores are 100 mm (3927 N @0.5) and 160 mm (10053 N @0.5). A plain cylinder drifts on air loss; for load holding use an external pilot check valve or the SAIL/BSAI lock variants. This SKU lacks a magnet, so position sensing is impossible.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X900
- ✓ 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 SI125X900 FAQ
Yes, the SI125X900 is discontinued. The direct replacement is the AirTAC SAI125X900. It shares the exact ISO 15552 mounting interface, 125 mm bore, 900 mm stroke, output force, G1/2 port, and accessories, so it drops directly into existing fixtures.
This 125 mm bore cylinder uses a G1/2 air port and an M27x2 rod thread. Theoretical forces 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; with a maximum force of 1251 kgf at 1.0 MPa. Speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X900
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X900 replacement — usually within 7-8 hours.