This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X50FA, 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 SI40X50FA
The AirTAC Airtac SI40 Standard Cylinder SI40X50FA is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 50mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X50FA, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke50 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X50FA
- 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 SI40X50FA
The AirTAC SI40X50FA is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 50mm stroke, delivering 628N push force at 0.5MPa via a G1/4 port. AirTAC replaced it with the SAI40X50FA, a direct upgrade retaining the exact FA flange mounting interface, bore, and force.
The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This specific SKU lacks a magnet (-S), so it cannot accept a CS1-B or DS1-B sensor.
Airtac SI40 Standard Cylinder SI40X50FA Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X50FA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X50FA |
| Bore size | Ø40 mm |
| Stroke | 50 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 SAI40X50FA 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 SAI40X50FA 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 SI40X50FA
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×50 | 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 SI40X50FA Is Used
Short-Stroke Clamping
Ideal for 50mm clamping actions in machining fixtures where 628N of push force securely holds parts.
Package Diverting
Provides rapid 50mm actuation for diverting small packages on a conveyor line at speeds up to 800 mm/s.
Gate Ejection
Delivers reliable ejection force for small parts or gates in light assembly machinery using the FA flange mount.
Replacing the Airtac SI40 Standard Cylinder SI40X50FA with the SAI40X50FA
To replace the discontinued SI40X50FA, order the SAI40X50FA, ensuring you keep the FA flange mounting, 40mm bore, 50mm stroke, and G1/4 port. If sizing up or down, neighboring bores are 32mm (402N push @0.5MPa) and 50mm (982N push @0.5MPa). Note that this non-magnetic SKU cannot support position sensing; if you need switches, select an SAI40X50S equivalent and use current AirTAC sensors. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding, consider an external pilot check valve or the SAIL/BSAI lock variants. The SAI family also adds the SAIF self-valve option (bores 32-100) which the SI lacked.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X50FA
- ✓ 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 SI40X50FA FAQ
Yes, the SI40X50FA is discontinued. The direct replacement is the SAI40X50FA. It is dimensionally interchangeable per ISO 15552, matching the 40mm bore, 50mm stroke, G1/4 port, and FA flange interface.
It uses a G1/4 air port. Force output is 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max of 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X50FA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X50FA replacement — usually within 7-8 hours.