This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X270N, 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 SI125X270N
The AirTAC SI125 Standard Cylinder SI125X270N is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 270mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X270N, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke270 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X270N
- 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 SI125X270N
The AirTAC SI125X270N is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 270 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. The direct replacement is the SAI125X270N, matching the interface, force, and mounting.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life. This SKU lacks a magnet, so it cannot take a sensor. The NBR seal supports -20 to +70 C (Viton H raises this to 150 C).
Airtac SI125 Standard Cylinder SI125X270N Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X270N |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X270N |
| Bore size | Ø125 mm |
| Stroke | 270 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 SAI125X270N 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 SAI125X270N 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 SI125X270N
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×270 | 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 SI125X270N Is Used
Heavy Press Operations
Applies 6136 N of thrust at 0.5 MPa for forming, stamping, and pressing heavy assemblies securely.
Industrial Automation
Drives large clamps and heavy-duty indexing mechanisms at 30-500 mm/s within ISO 15552 fixtures.
Replacing the Airtac SI125 Standard Cylinder SI125X270N with the SAI125X270N
To replace the SI125X270N, order the SAI125X270N. Verify the ISO 15552 mounting interface, 125 mm bore, 270 mm stroke, G1/2 port (PT/G/NPT), and M27x2 rod thread. Since this SKU lacks the -S magnet, it cannot accept CS1-B/DS1-B sensors. For loads needing holding on air loss, use an external rod lock or pilot check valve, as the cushion only decelerates. At 270 mm stroke, minimize side-load rod-bending by using guide rails. If sizing up or down, neighboring bores (100/160) shift the 0.5 MPa push force from 3927 N to 10053 N.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X270N
- ✓ 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 SI125X270N FAQ
Yes, the SI125X270N is discontinued. The direct replacement is the SAI125X270N. It is dimensionally interchangeable per ISO 15552, keeping the same 125 mm bore, 270 mm stroke, force, G1/2 port, and mounting.
The G1/2 port bore delivers push 6136 N and pull 5734 N at 0.5 MPa, push 8590 N at 0.7 MPa, push 11045 N at 0.9 MPa, and a max force of 1251 kgf at 1.0 MPa. Speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X270N
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X270N replacement — usually within 7-8 hours.