This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X150FB, 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 SI125X150FB
The AirTAC Airtac SI125 Standard Cylinder SI125X150FB is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 150mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X150FB, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke150 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X150FB
- 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 SI125X150FB
The AirTAC SI125X150FB is a discontinued double-acting ISO 15552 profile cylinder with an FB flange mount, delivering 6136 N push force at 0.5 MPa through its 125 mm bore and 150 mm stroke. Because this legacy unit is end-of-life, AirTAC specifies the SAI125X150FB as the direct replacement. It retains the same G1/2 port, M27x2 rod thread, and 32 mm rod, ensuring a true ISO 15552 mounting-interface swap.
The SAI upgrade introduces a refined piston seal using two Y-shaped one-way elements for lower start-up pressure and extended life. This SKU lacks the -S magnet, so it cannot accept CS1-B or DS1-B sensors. If high heat is a factor, a Viton H seal option extends operation to 150 C.
Airtac SI125 Standard Cylinder SI125X150FB Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X150FB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X150FB |
| Bore size | Ø125 mm |
| Stroke | 150 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 SAI125X150FB 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 SAI125X150FB 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 SI125X150FB
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×150 | 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 SI125X150FB Is Used
Heavy Press Forming
Drives large stamping and forming tools with 6136 N thrust at 0.5 MPa, utilizing the FB flange to handle severe lateral stress during metal deformation.
Bulk Material Diversion
Actuates heavy lane diverters and sorting gates on high-capacity conveyor lines, relying on the 125 mm bore for authoritative push force.
Replacing the Airtac SI125 Standard Cylinder SI125X150FB with the SAI125X150FB
To replace the discontinued SI125X150FB, order the SAI125X150FB. Verify your ISO 15552 interface dimensions, the FB flange mounting hardware, the 150 mm stroke, and the G1/2 port. This non-magnetic SKU cannot support position sensing; if switches are needed, migrate to an SAI model with the S suffix for current AirTAC sensors. Operating speed is 30-500 mm/s. For sizing alternatives, a 100 mm bore yields 3927 N push at 0.5 MPa, while a 160 mm bore provides 10053 N. Remember that a standard cylinder drifts without live air—the cushion only decelerates the stroke end. For load holding on air loss, use an external pilot check valve or the SAIL lock variant. The SAI family also adds the SAIF valve and BSAI clamp-lock options the SI lacked.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X150FB
- ✓ 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 SI125X150FB FAQ
Yes, the SI125X150FB is discontinued. The direct replacement is the SAI125X150FB. It shares the identical ISO 15552 mounting interface, 125 mm bore, 150 mm stroke, FB flange, and G1/2 port, fitting directly into your existing fixtures.
It features a G1/2 port. At 0.5 MPa it provides 6136 N push and 5734 N pull force. 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.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X150FB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X150FB replacement — usually within 7-8 hours.