This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X15S, 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 SI125X15S
The AirTAC SI125 Standard Cylinder SI125X15S 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 SAI125X15S, 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 → SAI125X15S
- 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 SI125X15S
The AirTAC SI125X15S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 15 mm stroke. It delivers 6136 N push force at 0.5 MPa through a G1/2 port. AirTAC replaced this legacy unit with the SAI125X15S, a direct sharing the exact ISO 15552 mounting interface, bore, stroke, output force, and accessories.
The SAI125X15S upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure and longer life. The SAI family also introduces SAIL, SAIF, and BSAI lock variants the SI lacked. Your SI125X15S includes a piston magnet for CS1-B/DS1-B switches; the SAI replacement uses current AirTAC switches.
Airtac SI125 Standard Cylinder SI125X15S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X15S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X15S |
| 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 SAI125X15S 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 SAI125X15S 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 SI125X15S
| 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 SI125X15S Is Used
Heavy-Duty Clamping
Secures large metal castings during CNC machining using the full 6136 N push force at 0.5 MPa.
Press Fit Assembly
Drives bearings into heavy housings over a short 15 mm stroke with high rigidity and precise end-positioning.
Pallet Stopping
Halts loaded pallets on conveyors, relying on the 125 mm bore and adjustable air cushions to absorb impact.
Replacing the Airtac SI125 Standard Cylinder SI125X15S with the SAI125X15S
To replace the discontinued SI125X15S, order the SAI125X15S. Confirm the ISO 15552 mounting interface, 125 mm bore, 15 mm stroke, G1/2 port (PT/G/NPT), and mounting accessory. The -S suffix means a magnet is present for CS1-B/DS1-B sensors; a no-S SKU cannot take a sensor. Sizing both ways: a 100 mm bore gives 3927 N push at 0.5 MPa, while a 160 mm bore gives 10053 N. Note that a plain SI/SAI does not hold load without live air; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X15S
- ✓ 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 SI125X15S FAQ
Yes, the SI125X15S is discontinued. The direct replacement is the SAI125X15S. It shares the same ISO 15552 mounting interface, 125 mm bore, 15 mm stroke, output force, and G1/2 port, fitting existing fixtures perfectly.
This 125 mm bore cylinder has a G1/2 port. The thrust is 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, and a theoretical max of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X15S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X15S replacement — usually within 7-8 hours.