This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX900SN, 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 SI125BX900SN
The AirTAC SI125 Standard Cylinder SI125BX900SN is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 900mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX900SN, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke900 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX900SN
- 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 SI125BX900SN
The AirTAC SI125BX900SN is a discontinued double-acting ISO 15552 profile cylinder featuring a 125mm bore, 900mm stroke, SUS304 stainless piston rod, NBR seals, and a piston magnet. Delivering 6136N push force at 0.5MPa, it is replaced by the SAI125BX900SN. This direct successor shares the exact ISO 15552 mounting interface, G1/2 port, and output force.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family adds SAIL, SAIF, and BSAI lock variants absent in the SI line. Your existing CS1-B/DS1-B switches fit the SI magnet, while the SAI uses current AirTAC sensors.
Airtac SI125 Standard Cylinder SI125BX900SN Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX900SN |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX900SN |
| Bore size | Ø125 mm |
| Stroke | 900 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 SAI125BX900SN 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 SAI125BX900SN 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 SI125BX900SN
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×900 | 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 SI125BX900SN Is Used
Heavy Press Staging
Ideal for positioning heavy metal blanks at 6136N push force into large stamping presses, utilizing the 900mm extension to reach deep into the work cell.
Pallet Reject Arm
The SUS304 stainless rod and 125mm bore provide the robust, corrosion-resistant thrust needed to shove overloaded pallets off high-speed sortation conveyors.
Long-Reach Diverter
Leveraging the 900mm stroke to shift large automotive components between parallel assembly lines, requiring external guides to manage the extended rod length.
Replacing the Airtac SI125 Standard Cylinder SI125BX900SN with the SAI125BX900SN
To replace the SI125BX900SN, order the SAI125BX900SN. Verify your ISO 15552 mounting accessories (LB, FA, CA, TC), the G1/2 port, and the M27x2 rod thread. The SAI is a direct. If sizing alternatives, a 100mm bore yields 3927N push at 0.5MPa, while a 160mm bore yields 10053N. This 900mm stroke demands external guides to prevent rod bending and side-load wear. For load holding on air loss, note that cushions only decelerate; use an external pilot check valve or the SAIL/BSAI lock variant. The NBR seals suit -20 to +70C; choose Viton H for 150C. The -B rod offers corrosion resistance.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX900SN
- ✓ 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 SI125BX900SN FAQ
Yes, the SI125BX900SN is discontinued. The direct replacement is the SAI125BX900SN. It shares the same ISO 15552 mounting interface, 125mm bore, 900mm stroke, G1/2 port, and output force, fitting your existing fixtures perfectly.
It features a G1/2 air port. At 0.5MPa it provides 6136N push and 5734N pull force. At 0.7MPa push is 8590N, and at 0.9MPa it is 11045N. The theoretical max force is 1251kgf at 1.0MPa. Speed is 30-500mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX900SN
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX900SN replacement — usually within 7-8 hours.