This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X125FA, 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 SI40 Standard Cylinder SI40X125FA
The AirTAC Airtac SI40 Standard Cylinder SI40X125FA is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 125mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X125FA, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke125 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X125FA
- 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 SI40 Standard Cylinder SI40X125FA
The AirTAC SI40X125FA is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 125mm stroke. It delivers 628N push force at 0.5MPa via a G1/4 port. The direct replacement is the SAI40X125FA, matching the exact FA flange mounting, M12x1.25 rod thread, and output force.
The SAI upgrade features a revised piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. For applications needing load holding, the SAI family adds SAIL and BSAI lock variants absent in the SI line. Note this specific SKU lacks a magnet (-S), meaning it cannot accept CS1-B/DS1-B sensors.
Airtac SI40 Standard Cylinder SI40X125FA Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X125FA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X125FA |
| Bore size | Ø40 mm |
| Stroke | 125 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| Rod thread | M12×1.25 |
| 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 – 800 mm/s |
| Cushion | Adjustable, 27 mm |
| Max standard stroke | Up to 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI40X125FA carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 kgf | |
The SAI40X125FA produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI40 Standard Cylinder SI40X125FA
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×125 | 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 SI40 Standard Cylinder SI40X125FA Is Used
Clamp Actuation
Provides 628N of clamping force at 0.5MPa for securing mid-weight workpieces during machining or welding operations.
Package Diverting
Drives 125mm stroke diverting arms or gating mechanisms on material handling lines with a safe 377N working load.
Part Ejection
Ejects molded or stamped components from press beds, utilizing the 32kg vertical lift capacity to clear tooling efficiently.
Replacing the Airtac SI40 Standard Cylinder SI40X125FA with the SAI40X125FA
To replace the SI40X125FA, order the SAI40X125FA. Verify the ISO 15552 FA flange interface, 40mm bore, 125mm stroke, G1/4 port (PT/G/NPT thread options), and M12x1.25 rod. Because this SKU has no magnet, it cannot support position sensing; if switches are needed, specify an SAI40X125FAS. For sizing alternatives, a 32mm bore yields 402N push at 0.5MPa, while a 50mm bore provides 982N. Remember that a standard cylinder does not hold load without live air—the cushions only decelerate. For secure holding, use an external pilot check valve or select the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X125FA
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI40 Standard Cylinder SI40X125FA FAQ
Yes, the SI40X125FA is discontinued. The direct replacement is the SAI40X125FA. It shares the identical ISO 15552 FA flange mounting interface, 40mm bore, 125mm stroke, G1/4 port, and output force, fitting directly into existing fixtures.
This 40mm bore cylinder features a G1/4 air port and provides 628N push and 528N pull force at 0.5MPa. At 0.7MPa it pushes 879N, and 1130N at 0.9MPa. The theoretical maximum force is 128kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X125FA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X125FA replacement — usually within 7-8 hours.