This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X450SFA, 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 SI40X450SFA
The AirTAC SI40 Standard Cylinder SI40X450SFA is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 450mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X450SFA, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke450 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X450SFA
- 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 SI40X450SFA
The AirTAC SI40X450SFA is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 450mm stroke. Delivering 628N push force at 0.5MPa via a G1/4 port, it is replaced by the SAI40X450SFA. This direct successor matches the exact ISO 15552 mounting interface, bore, stroke, output force and FA flange accessory, fitting existing fixtures perfectly.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life. The SAI family also adds SAIL, SAIF and BSAI lock variants the SI lacked. This -S SKU includes a piston magnet for CS1-B/DS1-B sensors; the SAI uses current AirTAC switches.
Airtac SI40 Standard Cylinder SI40X450SFA Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X450SFA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X450SFA |
| Bore size | Ø40 mm |
| Stroke | 450 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 SAI40X450SFA 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 SAI40X450SFA 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 SI40X450SFA
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×450 | 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 SI40X450SFA Is Used
Carton Diverting
Ideal for pushing medium-weight packages on a packaging line, utilizing the 628N thrust and 450mm reach to divert items smoothly at transfer stations.
Pallet Stopper Gate
Deploys a 450mm stroke to actuate pallet stopping gates or positioning flaps, handling loads safely within the 32kg vertical lift capacity.
Fixture Ejection
Ejects machined parts from a fixture using the FA flange mount to secure the body, with the 16mm rod providing stable push force over the long stroke.
Replacing the Airtac SI40 Standard Cylinder SI40X450SFA with the SAI40X450SFA
To replace the SI40X450SFA, order the SAI40X450SFA. Verify the ISO 15552 interface, 40mm bore, 450mm stroke, G1/4 port (PT/G/NPT thread options), FA flange mount, and the -S magnet. For sizing, a 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N. At 0.7MPa this 40mm bore pushes 879N. A plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. Because the 450mm stroke is long, use an external guide to prevent rod bending and side-load wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X450SFA
- ✓ 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 SI40X450SFA FAQ
Yes, the SI40X450SFA is discontinued. The direct replacement is the SAI40X450SFA. It is a true ISO 15552 profile cylinder that matches the 40mm bore, 450mm stroke, 628N force, G1/4 port and FA flange mounting interface, dropping directly into existing fixtures.
The 40mm bore uses a G1/4 port with a 16mm rod and M12x1.25 thread. Force ratings are: 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical maximum of 128kgf at 1.0MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X450SFA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X450SFA replacement — usually within 7-8 hours.