This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX350, 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 SI125BX350
The AirTAC SI125 Standard Cylinder SI125BX350 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 350mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX350, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke350 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX350
- 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 SI125BX350
The AirTAC SI125BX350 is a discontinued double-acting ISO 15552 profile cylinder featuring a 125mm bore and 350mm stroke. It delivers 6136 N push force at 0.5 MPa and uses a G1/2 port. AirTAC replaced this legacy unit with the SAI125BX350 direct replacement, retaining the exact ISO 15552 mounting interface, stroke, force, and accessories.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. This specific SKU includes a SUS304 stainless steel rod (-B) for corrosion resistance but lacks a magnet, meaning it cannot accept position sensors.
Airtac SI125 Standard Cylinder SI125BX350 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX350 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX350 |
| Bore size | Ø125 mm |
| Stroke | 350 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 SAI125BX350 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 SAI125BX350 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 SI125BX350
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×350 | 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 SI125BX350 Is Used
Heavy Press Clamping
Secures large metal castings during machining operations, utilizing the 6136 N push force at 0.5 MPa to hold components rigidly against cutting forces.
Pallet Lift Gates
Actuates heavy loading dock gates where the 350mm stroke provides the necessary travel, and the SUS304 rod resists humid or wash-down environments.
Large Mold Ejection
Ejects dense molded products from hydraulic presses, requiring the robust 125mm bore and external guides to handle the 350mm extension without rod bending.
Replacing the Airtac SI125 Standard Cylinder SI125BX350 with the SAI125BX350
To replace the SI125BX350, order the SAI125BX350. Confirm the ISO 15552 mounting interface, the 350mm stroke, the G1/2 port (PT/G/NPT), and your specific mounting accessory (LB, FA, TC, etc.). Because this SKU lacks the -S magnet, it cannot support legacy CS1-B/DS1-B sensors; you must add external physical stops or use a sensed rod if position detection is required. For load holding, note that a standard cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. At 350mm stroke, prevent rod bending by guiding the load externally to avoid side-load forces. If downsizing, a 100mm bore gives 3927 N [email protected]; if upsizing, a 160mm bore provides 10053 N.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX350
- ✓ 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 SI125BX350 FAQ
Yes, the AirTAC SI125BX350 is discontinued. The direct replacement is the SAI125BX350. It is dimensionally interchangeable per ISO 15552, offering the same 125mm bore, 350mm stroke, output force, G1/2 port, and mounting interface.
This 125mm bore cylinder features a G1/2 port and M27x2 rod thread. Theoretical forces are: 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 maximum force of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX350
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX350 replacement — usually within 7-8 hours.