This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X500FB, 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 SI125X500FB
The AirTAC SI125 Standard Cylinder SI125X500FB is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 500mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X500FB, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke500 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X500FB
- 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 SI125X500FB
The AirTAC SI125X500FB is a discontinued double-acting ISO 15552 profile cylinder with an FB flange mount. Delivering 6136 N push force at 0.5 MPa through a G1/2 port, its direct successor is the SAI125X500FB. The SAI retains the same 125 mm bore, 500 mm stroke, and M27x2 rod thread, upgrading the assembly with a two Y-shaped one-way piston seal for lower start-up pressure and extended life.
Because this SKU lacks the -S magnet, it cannot accept CS1-B or DS1-B sensors. If your fixture requires load holding on air loss, note that the adjustable 40 mm cushions only decelerate; you must use an external rod lock, pilot check valve, or the SAI family's SAIL or BSAI clamp-lock variants.
Airtac SI125 Standard Cylinder SI125X500FB Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X500FB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X500FB |
| Bore size | Ø125 mm |
| Stroke | 500 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 SAI125X500FB 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 SAI125X500FB 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 SI125X500FB
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×500 | 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 SI125X500FB Is Used
Heavy Press Forming
Ideal for applying high clamp force in automated metal forming lines, utilizing the 6136 N push capacity at 0.5 MPa.
Pallet Diversion
Drives heavy-duty routing gates on assembly conveyors, with the FB flange ensuring rigid mounting under lateral stress.
Large Lift Gates
Actuates substantial material handling doors, requiring external guidance over the 500 mm stroke to prevent rod bending.
Replacing the Airtac SI125 Standard Cylinder SI125X500FB with the SAI125X500FB
To replace the discontinued SI125X500FB, order the SAI125X500FB. It is dimensionally interchangeable per the ISO 15552 mounting interface, matching the FB flange, 125 mm bore, 500 mm stroke, and G1/2 port. When sizing, verify force both ways: this class yields 6136 N push and 5734 N pull at 0.5 MPa. If you need less force, step down to an 80 mm bore (2513 N push); for more, a 160 mm bore provides 10053 N. Remember that a standard cylinder drifts without live air—the cushion only decelerates—so for suspended loads consider the SAIL lock or BSAI clamp-lock variant. Finally, at 500 mm of travel, prevent rod bending by guiding the load externally to avoid side-loading.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X500FB
- ✓ 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 SI125X500FB FAQ
Yes, the SI125X500FB is discontinued. The direct replacement is the SAI125X500FB. It is dimensionally interchangeable per ISO 15552, retaining the same FB flange, 125 mm bore, 500 mm stroke, and G1/2 port.
It features a G1/2 port and provides 6136 N push and 5734 N pull at 0.5 MPa. At 0.7 MPa push is 8590 N, at 0.9 MPa it is 11045 N, and the theoretical max is 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X500FB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X500FB replacement — usually within 7-8 hours.