This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X206S, 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 SI125X206S
The AirTAC SI125 Standard Cylinder SI125X206S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 206mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X206S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke206 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X206S
- 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 SI125X206S
The AirTAC SI125X206S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 206 mm stroke. It delivers 6136 N push force at 0.5 MPa. AirTAC replaced this legacy unit with the SAI125X206S, a direct upgrade retaining the exact ISO 15552 mounting interface, G1/2 port, and output force. Note that 206 mm is a nonstandard stroke length.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. It also adds SAIL, SAIF, and BSAI lock variants absent in the SI line. The -S suffix denotes a piston magnet for CS1-B/DS1-B switches.
Airtac SI125 Standard Cylinder SI125X206S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X206S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X206S |
| Bore size | Ø125 mm |
| Stroke | 206 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 SAI125X206S 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 SAI125X206S 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 SI125X206S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×206 | 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 SI125X206S Is Used
Heavy Stamping Press
Drives large platens and tooling dies where the 6136 N push force at 0.5 MPa is required for forming thick metal components.
Automated Clamp Fixture
Secures heavy machinery housings during machining operations, utilizing the robust 32 mm rod and adjustable 40 mm air cushions.
Replacing the Airtac SI125 Standard Cylinder SI125X206S with the SAI125X206S
To replace the SI125X206S, order the SAI125X206S. Verify your ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/2 air port, and the M27x2 rod thread. The 206 mm stroke is nonstandard; confirm exact end-of-stroke dimensions if replacing a unit in a tight fixture. For sizing, the 125 mm bore yields 6136 N push at 0.5 MPa; a neighboring 100 mm bore provides 3927 N, while a 160 mm bore offers 10053 N. Because stroke exceeds 300 mm, ensure adequate guide support to prevent rod bending and side-load wear. A plain cylinder drifts on air loss—the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X206S
- ✓ 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 SI125X206S FAQ
Yes, the SI125X206S is discontinued. The direct replacement is the SAI125X206S. It shares the same ISO 15552 mounting interface, 125 mm bore, 206 mm stroke, output force, and G1/2 port, fitting existing fixtures perfectly.
The 125 mm bore features a G1/2 port. It delivers 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 force of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X206S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X206S replacement — usually within 7-8 hours.