This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X540S, 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 SI40X540S
The AirTAC Airtac SI40 Standard Cylinder SI40X540S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 540mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X540S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke540 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X540S
- 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 SI40X540S
The AirTAC SI40X540S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 540mm stroke. It delivers 628N push force at 0.5MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI40X540S, a direct alternative retaining the exact ISO 15552 mounting interface, stroke, and output force.
The SAI upgrade features a refined piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. The family also adds SAIL, SAIF, and BSAI lock variants absent in the SI line.
Airtac SI40 Standard Cylinder SI40X540S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X540S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X540S |
| Bore size | Ø40 mm |
| Stroke | 540 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 SAI40X540S 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 SAI40X540S 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 SI40X540S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×540 | 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 SI40X540S Is Used
Carton Diverting
Pushes light packages on a packaging line using the 628N push force, with the 540mm stroke spanning wider transfer belts.
Pallet Gate Actuation
Opens and closes safety gates on pallet wrappers, where the G1/4 port and ISO 15552 mounts integrate easily.
Replacing the Airtac SI40 Standard Cylinder SI40X540S with the SAI40X540S
To replace the SI40X540S, order the SAI40X540S and verify the ISO 15552 mounting interface, M12x1.25 rod thread, G1/4 port, and the -S magnet for CS1-B/DS1-B sensors. If you need more force, the neighbouring 50mm bore yields 982N push at 0.5MPa; if less is acceptable, the 32mm bore provides 402N. Because the 540mm stroke invites rod bending, use an external guide to prevent side loads. Note that a plain cylinder drifts without live air; for load holding, specify a pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X540S
- ✓ 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 SI40X540S FAQ
Yes, the SI40X540S is discontinued. The direct replacement is the SAI40X540S, which shares the identical ISO 15552 mounting interface, 40mm bore, 540mm stroke, output force, and G1/4 port.
The 40mm bore uses a G1/4 port and M12x1.25 rod thread. It generates 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.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X540S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X540S replacement — usually within 7-8 hours.