This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX90S, 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 SI125AX90S
The AirTAC SI125 Standard Cylinder SI125AX90S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 90mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125AX90S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke90 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125AX90S
- 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 SI125AX90S
The AirTAC SI125AX90S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 90 mm stroke. It delivers 6136 N push force at 0.5 MPa through a G1/2 port. AirTAC replaced this legacy unit with the SAI125AX90S, a direct replacement sharing the exact ISO 15552 mounting interface, M27x2 rod thread, and 40 mm cushions.
The SAI upgrade features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This specific -A variant specifies a SUS420J2 stainless steel piston rod for corrosion resistance, while the -S magnet supports legacy CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125AX90S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX90S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX90S |
| Bore size | Ø125 mm |
| Stroke | 90 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 SAI125AX90S 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 SAI125AX90S 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 SI125AX90S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×90 | 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 SI125AX90S Is Used
Heavy Press Clamping
Secures large metal castings during machining operations, utilizing the 6136 N push force and SUS420J2 stainless rod to resist coolant corrosion.
Pallet Stopper Gate
Acts as a robust 90 mm stroke blocking gate in high-mass conveyor lines, safely halting loaded pallets up to the 313 kg vertical lift threshold.
Injection Mold Ejection
Drives heavy ejection pins on large molding machinery, relying on the 40 mm adjustable air cushions to absorb kinetic energy at stroke end.
Replacing the Airtac SI125 Standard Cylinder SI125AX90S with the SAI125AX90S
To replace the SI125AX90S, order the SAI125AX90S and verify the ISO 15552 mounting interface, 125 mm bore, 90 mm stroke, G1/2 port, and your specific mounting accessory. The -A suffix ensures you receive the SUS420J2 stainless rod, and the -S suffix confirms the piston magnet for current AirTAC switches. If you need to size up or down, neighbouring bores alter the 0.5 MPa push force significantly (e.g., 100 mm bore yields 3927 N; 160 mm bore yields 10053 N). Note that a plain cylinder drifts on air loss because the cushion only decelerates near stroke end; for load holding, specify the SAIL or BSAI lock variant, or use an external pilot check valve. Operating speed is 30-500 mm/s.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX90S
- ✓ 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 SI125AX90S FAQ
Yes, the SI125AX90S is discontinued. The direct replacement is the SAI125AX90S. It shares the identical ISO 15552 mounting interface, 125 mm bore, 90 mm stroke, output force, G1/2 port, and M27x2 rod thread, fitting directly into existing fixtures.
This 125 mm bore cylinder features a G1/2 air port and provides 6136 N push / 5734 N pull at 0.5 MPa. At 0.7 MPa push is 8590 N, and at 0.9 MPa it is 11045 N. The theoretical maximum force is 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX90S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125AX90S replacement — usually within 7-8 hours.