This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X750S, 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 SI125X750S
The AirTAC SI125 Standard Cylinder SI125X750S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 750mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X750S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke750 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X750S
- 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 SI125X750S
The AirTAC SI125X750S is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 750mm stroke, delivering 6136N push force at 0.5MPa via a G1/2 port. AirTAC replaced this legacy unit with the SAI125X750S, a direct upgrade retaining the exact ISO 15552 mounting interface, M27x2 rod thread, and 40mm cushions.
The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SAI family also introduces SAIL and BSAI lock variants the SI lacked. Your -S suffix means a piston magnet for CS1-B/DS1-B switches.
Airtac SI125 Standard Cylinder SI125X750S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X750S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X750S |
| Bore size | Ø125 mm |
| Stroke | 750 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 SAI125X750S 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 SAI125X750S 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 SI125X750S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×750 | 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 SI125X750S Is Used
Heavy Press Actuation
Drives large stamping or forming presses requiring 6136N thrust at 0.5MPa, utilizing the 750mm stroke for deep draw operations.
Large Material Ejection
Ejects heavy molded parts or fabricated components from machinery, relying on the 40mm adjustable cushions to decelerate at stroke ends.
Replacing the Airtac SI125 Standard Cylinder SI125X750S with the SAI125X750S
To replace the SI125X750S, order the SAI125X750S. Confirm the ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/2 port thread (PT/G/NPT), and the -S magnet for legacy CS1-B/DS1-B sensors. The SAI drops into existing fixtures with identical 125mm bore and 750mm stroke. For sizing, this bore yields 6136N push at 0.5MPa; if less force is needed, an 80mm bore provides 2513N, while a 160mm bore offers 10053N. Because a plain cylinder drifts without live air, use an external rod lock or pilot check valve for load holding, or specify the SAIL/BSAI lock variant. With a 750mm stroke, use external guides to prevent rod bending and side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X750S
- ✓ 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 SI125X750S FAQ
Yes, the SI125X750S is discontinued. The direct replacement is the AirTAC SAI125X750S. It is dimensionally interchangeable per ISO 15552, retaining the same 125mm bore, 750mm stroke, G1/2 port, and mounting interface.
The 125mm bore features a G1/2 port. It delivers 6136N push and 5734N pull at 0.5MPa, 8590N push at 0.7MPa, 11045N push at 0.9MPa, and a theoretical max force of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X750S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X750S replacement — usually within 7-8 hours.