This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X350SFA, 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 SI40X350SFA
The AirTAC Airtac SI40 Standard Cylinder SI40X350SFA 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 SAI40X350SFA, 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 → SAI40X350SFA
- 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 SI40X350SFA
The AirTAC SI40X350SFA is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 350mm stroke. It delivers 628N push force at 0.5MPa and uses a G1/4 port. AirTAC replaced this legacy unit with the SAI40X350SFA, a direct upgrade retaining the exact interface, force, and stroke.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure. The SAI family also adds SAIL, SAIF, and BSAI lock variants the SI lacked. Your -S magnet works with legacy CS1-B/DS1-B sensors.
Airtac SI40 Standard Cylinder SI40X350SFA Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X350SFA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X350SFA |
| 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 SAI40X350SFA 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 SAI40X350SFA 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 SI40X350SFA
| 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 SI40X350SFA Is Used
Package Diversion
Pushes medium-weight cartons at 628N push force onto secondary packaging lines using the FA flange mount.
Pallet Handling
Extends 350mm to index pallets or totes, requiring external guides to manage rod bending during transit.
Clamp Actuation
Secures workpieces with a 32kg vertical lift capacity, needing a pilot check valve to hold position safely.
Replacing the Airtac SI40 Standard Cylinder SI40X350SFA with the SAI40X350SFA
To replace the SI40X350SFA, order the SAI40X350SFA. Confirm the ISO 15552 mounting interface, 40mm bore, 350mm stroke, G1/4 port, and FA flange. The -S magnet enables CS1-B/DS1-B sensors. For sizing, a 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N. At 350mm, use external guides to prevent rod bending and side loads. A plain cylinder drifts without air; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X350SFA
- ✓ 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 SI40X350SFA FAQ
Yes, the SI40X350SFA is discontinued. The direct replacement is the SAI40X350SFA, which matches the 40mm bore, 350mm stroke, 628N force, G1/4 port, and ISO 15552 mounting interface.
It delivers 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, and a theoretical max of 128kgf at 1.0MPa. Operating speed is 30-800mm/s. The G1/4 port and M12x1.25 rod thread are fixed by the bore.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X350SFA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X350SFA replacement — usually within 7-8 hours.