This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X350S, 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 SI125X350S
The AirTAC SI125 Standard Cylinder SI125X350S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 350mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X350S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke350 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X350S
- 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 SI125X350S
The AirTAC SI125X350S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 350 mm stroke. It delivers 6136 N push force at 0.5 MPa through a G1/2 port. AirTAC replaced this legacy unit with the SAI125X350S, a direct replacement retaining the exact ISO 15552 mounting interface, bore, stroke, output force, and port size.
The SAI upgrade features a refined piston seal using two Y-shaped one-way elements for low start-up pressure and extended life. The SAI family also introduces lock and valve variants the SI lacked, and the original -S magnet works with legacy CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X350S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X350S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X350S |
| Bore size | Ø125 mm |
| Stroke | 350 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 SAI125X350S 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 SAI125X350S 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 SI125X350S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×350 | 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 SI125X350S Is Used
Heavy Press Operations
Ideal for high-tonnage pressing and forming tasks requiring the full 6136 N push force at 0.5 MPa over a 350 mm travel distance.
Large Pallet Handling
Drives heavy pallet manipulators and automated storage retrieval systems where robust 125 mm bore capacity is essential.
Automated Assembly Lifts
Raises substantial chassis or subassembly fixtures vertically, benefiting from the 313 kg safe lift margin with guided motion.
Replacing the Airtac SI125 Standard Cylinder SI125X350S with the SAI125X350S
To replace the SI125X350S, order the SAI125X350S and confirm the ISO 15552 mounting interface, 125 mm bore, 350 mm stroke, G1/2 port, and your specific mounting accessory. If sizing both ways, neighboring bores offer different force classes, but at 0.5 MPa this unit pushes 6136 N and pulls 5734 N. Because the 350 mm stroke is long, use external guides to prevent rod bending and side-load damage. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock or pilot check valve for load holding, or specify the SAIL or BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X350S
- ✓ 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 SI125X350S FAQ
Yes, the SI125X350S is discontinued. The direct replacement is the SAI125X350S. It is dimensionally interchangeable per the ISO 15552 mounting interface, keeping the same 125 mm bore, 350 mm stroke, output force, G1/2 port, and mounting accessories.
The G1/2 port feeds a 32 mm rod. At 0.5 MPa it pushes 6136 N and pulls 5734 N. 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. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X350S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X350S replacement — usually within 7-8 hours.