This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X350FA, 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 SI40X350FA
The AirTAC Airtac SI40 Standard Cylinder SI40X350FA is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 350mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X350FA, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke350 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X350FA
- 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 SI40X350FA
The AirTAC SI40X350FA is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 350 mm stroke. Delivering 628 N push at 0.5 MPa via a G1/4 port, it is replaced by the SAI40X350FA. This direct successor shares the identical ISO 15552 mounting interface, M12x1.25 rod thread and FA flange, fitting existing fixtures perfectly.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. This SKU lacks a magnet so cannot take a sensor. For high heat, Viton H seals raise limits to 150 C; for load holding, explore SAIL or BSAI lock variants.
Airtac SI40 Standard Cylinder SI40X350FA Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X350FA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X350FA |
| Bore size | Ø40 mm |
| Stroke | 350 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 SAI40X350FA 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 SAI40X350FA 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 SI40X350FA
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | 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 SI40 Standard Cylinder SI40X350FA Is Used
Material Diversion
Drives sorting flaps on packaging lines, utilizing the 628 N push force to redirect mid-weight cartons reliably at high cycle rates.
Vertical Lift Gates
Raises lightweight access gates or safety hoods, providing a stable 32 kg vertical lift capacity when paired with external guidance.
Fixture Clamping
Secures workholding fixtures via the FA flange mount, applying consistent 528 N pull force to hold aluminium housings during machining.
Replacing the Airtac SI40 Standard Cylinder SI40X350FA with the SAI40X350FA
To replace the SI40X350FA, order the SAI40X350FA. Confirm the ISO 15552 FA flange interface, 40 mm bore, 350 mm stroke, G1/4 port (PT/G/NPT thread) and M12x1.25 rod. Because this is a no-magnet SKU, it cannot accept CS1-B/DS1-B sensors. If sizing up or down, neighbouring bores are 32 mm (402 N push) and 50 mm (982 N push) at 0.5 MPa. A plain cylinder drifts on air loss—the 27 mm cushion only decelerates; use a pilot check valve or SAIL lock to hold loads. At 350 mm, prevent rod bending by guiding external loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X350FA
- ✓ 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 SI40X350FA FAQ
Yes, the SI40X350FA is discontinued. The direct replacement is the SAI40X350FA. It provides identical ISO 15552 mounting dimensions, 40 mm bore, 350 mm stroke, output force, G1/4 port and FA flange, fitting directly into existing setups.
This double-acting cylinder uses a G1/4 air port. Force output is 628 N push and 528 N pull at 0.5 MPa, 879 N push at 0.7 MPa, 1130 N push at 0.9 MPa, with a theoretical maximum of 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X350FA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X350FA replacement — usually within 7-8 hours.