This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX290S, 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 SI125BX290S
The AirTAC SI125 Standard Cylinder SI125BX290S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 290mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX290S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke290 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX290S
- 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 SI125BX290S
The AirTAC SI125BX290S is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 290mm stroke. It delivers 6136N push force at 0.5MPa via a G1/2 port. The direct replacement is the SAI125BX290S, matching the interface, force, and mounting exactly.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life.
Airtac SI125 Standard Cylinder SI125BX290S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX290S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX290S |
| Bore size | Ø125 mm |
| Stroke | 290 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 SAI125BX290S 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 SAI125BX290S 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 SI125BX290S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×290 | 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 SI125BX290S Is Used
Heavy Stamping Press
Drives large platens and heavy tooling where the 6136N push force at 0.5MPa is required for forming operations.
Automated Clamp Station
Secures large fabricated components during machining, relying on the 40mm adjustable air cushions for smooth end-of-stroke deceleration.
Replacing the Airtac SI125 Standard Cylinder SI125BX290S with the SAI125BX290S
To replace the SI125BX290S, order the SAI125BX290S. Confirm the ISO 15552 mounting interface, the 125mm bore, 290mm stroke, G1/2 port, and your specific mounting accessory. The SAI is dimensionally interchangeable per ISO 15552 and drops into existing fixtures. If sizing up or down, neighboring bores are 100mm (3927N push @0.5MPa) and 160mm (10053N push @0.5MPa). Because this is a 290mm stroke, ensure adequate guiding to prevent rod-bending side loads. A plain cylinder does not hold load without live air; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants. The SAIF self-valve variant is unavailable for 125mm bores.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX290S
- ✓ 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 SI125BX290S FAQ
Yes, the SI125BX290S is discontinued. The direct replacement is the SAI125BX290S. It is dimensionally interchangeable per ISO 15552, retaining the same 125mm bore, 290mm stroke, G1/2 port, and mounting interface. You simply order the SAI equivalent.
This 125mm bore cylinder uses a G1/2 air port. It generates 6136N push and 5734N pull at 0.5MPa, 8590N push at 0.7MPa, 11045N push at 0.9MPa, and a theoretical maximum of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX290S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX290S replacement — usually within 7-8 hours.