This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX25S, 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 SI125AX25S
The AirTAC SI125 Standard Cylinder SI125AX25S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 25mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125AX25S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke25 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125AX25S
- 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 SI125AX25S
The AirTAC SI125AX25S is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore, 25mm stroke, and an SUS420J2 stainless steel rod. It delivers 6136N of push force at 0.5MPa and uses a G1/2 air port. The direct replacement is the current-production SAI125AX25S, which retains the exact same ISO 15552 mounting interface, bore, stroke, output force, and porting for a seamless fixture retrofit.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for lower start-up pressure and extended life. This SI125AX25S includes a piston magnet for legacy CS1-B/DS1-B sensors, while the SAI family introduces lock and clamp variants like the SAIL and BSAI that the original SI line lacked.
Airtac SI125 Standard Cylinder SI125AX25S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX25S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX25S |
| Bore size | Ø125 mm |
| Stroke | 25 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 SAI125AX25S 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 SAI125AX25S 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 SI125AX25S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×25 | 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 SI125AX25S Is Used
Heavy Stamping Press
Drives high-tonnage stamping and forming dies where the short 25mm stroke and 6136N push force at 0.5MPa deliver rapid, powerful impact cycles.
Pallet Stopper Gate
Acts as a robust 313kg vertical lift or horizontal blocking mechanism in conveyor systems, utilizing the SUS420J2 stainless rod for corrosion resistance.
Injection Mold Clamp
Secures heavy industrial molds using the 125mm bore's massive 1251kgf maximum theoretical force, relying on the G1/2 port for high-volume air supply.
Replacing the Airtac SI125 Standard Cylinder SI125AX25S with the SAI125AX25S
To replace the discontinued SI125AX25S, order the SAI125AX25S. Verify your existing fixture's ISO 15552 mounting interface, the 125mm bore, the 25mm stroke, and the G1/2 port (available in PT, G, or NPT). Confirm the SUS420J2 stainless rod option and the -S magnet for position sensing. If you need to scale up or down, neighboring bores offer different force classes: a 100mm bore yields 3927N push at 0.5MPa, while a 160mm bore provides 10053N. Note that a standard cylinder drifts on air loss because the 40mm adjustable air cushion only decelerates at stroke end; for secure load holding, specify the SAIL or BSAI lock variant, or use an external rod lock. The standard speed range is 30-500mm/s.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX25S
- ✓ 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 SI125AX25S FAQ
Yes, the SI125AX25S is discontinued. The direct replacement is the AirTAC SAI125AX25S. It is dimensionally interchangeable per ISO 15552, retaining the same 125mm bore, 25mm stroke, G1/2 port, and mounting interface. The SAI simply upgrades the piston seal to two Y-shaped elements for lower start-up pressure.
The 125mm bore features a G1/2 air port and an M27x2 rod thread. Force output is 6136N push and 5734N pull at 0.5MPa, 8590N push at 0.7MPa, 11045N push at 0.9MPa, and a maximum theoretical force of 1251kgf at 1.0MPa. The standard speed range is 30-500mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX25S
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