This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X720S, 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 SI40X720S
The AirTAC Airtac SI40 Standard Cylinder SI40X720S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 720mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X720S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke720 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X720S
- 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 SI40X720S
The AirTAC SI40X720S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 720 mm stroke, delivering 628 N push force at 0.5 MPa via its G1/4 port. AirTAC replaced this legacy unit with the SAI40X720S, a direct upgrade retaining the exact interface, bore, stroke, and mounting.
The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SAI family also introduces SAIL, SAIF, and BSAI lock variants absent in the SI line.
Airtac SI40 Standard Cylinder SI40X720S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X720S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X720S |
| Bore size | Ø40 mm |
| Stroke | 720 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 SAI40X720S 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 SAI40X720S 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 SI40X720S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×720 | 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 SI40X720S Is Used
Long-Stroke Diversion
Pushes packages across a 720 mm conveyor lane using the 628 N push force at 0.5 MPa, requiring external guides to prevent rod bending over the long travel.
Parts Ejection
Cycles at 30-800 mm/s to eject machined components from a fixture, with adjustable 27 mm air cushions decelerating the rod at both ends.
Replacing the Airtac SI40 Standard Cylinder SI40X720S with the SAI40X720S
To replace the SI40X720S, order the SAI40X720S and verify your ISO 15552 mounting interface, G1/4 port thread (PT/G/NPT), and the -S magnet for CS1-B/DS1-B legacy sensors (the SAI uses current AirTAC switches). If you need more force, the neighbouring 50 mm bore yields 982 N push at 0.5 MPa; if less is acceptable, the 32 mm bore provides 402 N. Because this is a 720 mm stroke, add external guides to prevent rod bending and side-load damage. A plain cylinder drifts on air loss—the cushion only decelerates—so use a pilot check valve or the SAIL/BSAI lock variant to hold loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X720S
- ✓ 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 SI40X720S FAQ
Yes, the SI40X720S is discontinued. The direct replacement is the SAI40X720S, which maintains the identical ISO 15552 mounting interface, 40 mm bore, 720 mm stroke, force, and G1/4 port. It fits existing fixtures perfectly while offering an upgraded piston seal.
The 40 mm bore features a G1/4 air port and a 16 mm rod. It delivers 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, and a theoretical maximum of 128 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X720S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X720S replacement — usually within 7-8 hours.