This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX15S, 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 SI125AX15S
The AirTAC SI125 Standard Cylinder SI125AX15S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 15mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125AX15S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke15 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125AX15S
- 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 SI125AX15S
The AirTAC SI125AX15S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 15 mm stroke, delivering 6136 N push force at 0.5 MPa through its G1/2 port. AirTAC replaced this legacy unit with the SAI125AX15S, a direct sharing the exact mounting interface, M27x2 rod thread, and 40 mm cushions. The SAI upgrade introduces a two Y-shaped one-way piston seal for lower start-up pressure and longer life. This -A variant features a SUS420J2 stainless steel rod, and the -S magnet supports CS1-B/DS1-B sensors.
The SAI family also adds SAIL, SAIF, and BSAI lock variants absent in the SI line. Note that a standard cylinder drifts without live air; cushions only decelerate, so use a lock variant for holding.
Airtac SI125 Standard Cylinder SI125AX15S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX15S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX15S |
| Bore size | Ø125 mm |
| Stroke | 15 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 SAI125AX15S 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 SAI125AX15S 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 SI125AX15S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×15 | 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 SI125AX15S Is Used
Heavy-Duty Clamping
Secures large metal castings during CNC machining using the 6136 N push force, with the SUS420J2 rod resisting coolant corrosion.
High-Force Ejection
Ejects dense molded parts from presses rapidly over the 15 mm stroke, relying on the 30-500 mm/s speed range.
Pallet Stopping
Acts as a robust end-stop for heavy pallets on conveyor lines, absorbing impact via the 40 mm adjustable air cushions.
Replacing the Airtac SI125 Standard Cylinder SI125AX15S with the SAI125AX15S
To replace the discontinued SI125AX15S, order the SAI125AX15S, ensuring the ISO 15552 mounting interface, 125 mm bore, 15 mm stroke, G1/2 port, and SUS420J2 rod are retained. If you need less force, the 100 mm bore provides 3927 N at 0.5 MPa; if you need more, the 160 mm bore yields 10053 N. The -S magnet works with legacy CS1-B/DS1-B switches, while the SAI uses current AirTAC sensors. Because the 15 mm stroke is short, side-load risks are minimal, but always verify alignment. A plain cylinder does not hold load without air; for secure holding, select the SAIL or BSAI lock variant, or use an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX15S
- ✓ 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 SI125AX15S FAQ
Yes, the SI125AX15S is discontinued. The direct replacement is the SAI125AX15S. It is dimensionally interchangeable per ISO 15552, matching the 125 mm bore, 15 mm stroke, G1/2 port, and mounting accessories, but features an upgraded piston seal for lower start-up pressure.
The bore is 125 mm with a G1/2 port. At 0.5 MPa it provides 6136 N push and 5734 N pull force. At 0.7 MPa it pushes 8590 N, and 11045 N at 0.9 MPa. The theoretical maximum force is 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX15S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125AX15S replacement — usually within 7-8 hours.