This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X372S, 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 SI40X372S
The AirTAC Airtac SI40 Standard Cylinder SI40X372S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 372mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X372S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke372 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X372S
- 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 SI40X372S
The AirTAC SI40X372S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 372mm stroke. It delivers 628N push force at 0.5MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI40X372S, a direct upgrade retaining the exact ISO 15552 mounting interface, bore, stroke, output force, and port size.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This -S model includes a piston magnet for CS1-B/DS1-B sensors, while the SAI family adds SAIL, SAIF, and BSAI lock variants the SI lacked.
Airtac SI40 Standard Cylinder SI40X372S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X372S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X372S |
| Bore size | Ø40 mm |
| Stroke | 372 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 SAI40X372S 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 SAI40X372S 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 SI40X372S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×372 | 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 SI40X372S Is Used
Package Diversion
Drives diverting arms on packaging lines, using the 372mm stroke to push cartons cleanly onto adjacent routing belts.
Light Lift Gates
Actuates lightweight vertical gating mechanisms where the 628N push force at 0.5MPa easily overcomes gravity and friction.
Pallet Stops
Deploys pneumatic stop pins at pallet transfer stations, extending 372mm to halt incoming loads securely.
Replacing the Airtac SI40 Standard Cylinder SI40X372S with the SAI40X372S
To replace the discontinued SI40X372S, order the SAI40X372S. Confirm the ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/4 port thread (PT, G, or NPT), and the magnet requirement. This 372mm stroke exceeds 300mm, so use external guides to prevent rod bending and side-load damage. If sizing alternatives, a 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N. Note that a plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X372S
- ✓ 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 SI40X372S FAQ
Yes, the SI40X372S is discontinued. The direct replacement is the SAI40X372S. It shares the identical ISO 15552 mounting interface, 40mm bore, 372mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly while upgrading the piston seal.
The 40mm bore features a G1/4 air port and M12x1.25 rod thread. 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 128kgf at 1.0MPa. Operating speed is 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X372S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X372S replacement — usually within 7-8 hours.