This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX475S, 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 SI125BX475S
The AirTAC SI125 Standard Cylinder SI125BX475S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 475mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX475S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke475 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX475S
- 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 SI125BX475S
The AirTAC SI125BX475S is a discontinued double-acting ISO 15552 profile cylinder featuring a SUS304 stainless piston rod and a 475 mm stroke. Delivering 6136 N push force at 0.5 MPa via a G1/2 port, it is replaced by the SAI125BX475S. This direct successor shares the exact ISO 15552 mounting interface, bore, and force ratings.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and longevity. The SAI family also adds SAIL, SAIF, and BSAI lock variants absent from the SI line.
Airtac SI125 Standard Cylinder SI125BX475S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX475S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX475S |
| Bore size | Ø125 mm |
| Stroke | 475 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 SAI125BX475S 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 SAI125BX475S 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 SI125BX475S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×475 | 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 SI125BX475S 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 firmly against cutting forces.
Pallet Diverting
Actuates heavy-duty routing gates on automated assembly lines, where the 475 mm stroke provides the reach needed to redirect wide product flows.
Replacing the Airtac SI125 Standard Cylinder SI125BX475S with the SAI125BX475S
To replace the SI125BX475S, order the SAI125BX475S, confirming the ISO 15552 mounting interface, G1/2 port, M27x2 rod thread, and the -S magnet for legacy CS1-B/DS1-B sensors (the SAI uses current AirTAC switches). The SUS304 rod (-B) resists corrosion versus standard carbon steel. If sizing down, a 100 mm bore yields 3927 N push at 0.5 MPa; sizing up to 160 mm provides 10053 N. A 475 mm stroke demands external guides to prevent rod bending under side loads. Plain cylinders drift without air; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX475S
- ✓ 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 SI125BX475S FAQ
Yes, the SI125BX475S is discontinued. The direct replacement is the SAI125BX475S. It is dimensionally interchangeable per the ISO 15552 mounting interface, retaining the same 125 mm bore, 475 mm stroke, force, G1/2 port, and mounting accessories.
The 125 mm bore generates a push force of 6136 N and a pull force of 5734 N at 0.5 MPa. At 0.7 MPa the push force is 8590 N, and at 0.9 MPa it is 11045 N. The theoretical maximum force is 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX475S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX475S replacement — usually within 7-8 hours.