This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X520S, 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 SI40X520S
The AirTAC Airtac SI40 Standard Cylinder SI40X520S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 520mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X520S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke520 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X520S
- 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 SI40X520S
The AirTAC SI40X520S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 520mm stroke, delivering 628N push force at 0.5MPa. It is superseded by the SAI40X520S. This direct replacement retains the exact G1/4 port, M12x1.25 rod thread, and mounting interface, fitting existing fixtures seamlessly.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family adds SAIL, SAIF, and BSAI lock variants the SI lacked. Your -S magnet works with legacy CS1-B/DS1-B sensors, while the SAI uses current AirTAC switches.
Airtac SI40 Standard Cylinder SI40X520S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X520S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X520S |
| Bore size | Ø40 mm |
| Stroke | 520 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 SAI40X520S 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 SAI40X520S 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 SI40X520S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×520 | 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 SI40X520S Is Used
Long-Stroke Diversion
Pushes packages across transfer lines with its 520mm reach, utilizing the 628N thrust to overcome lateral friction.
Vertical Lift Gates
Raises lightweight access panels, safely managing loads around 32kg while benefiting from adjustable end cushions.
Component Ejection
Extracts machined parts from fixtures, where the 40mm bore provides sufficient force without damaging the product.
Replacing the Airtac SI40 Standard Cylinder SI40X520S with the SAI40X520S
To replace the SI40X520S, order the SAI40X520S, confirming the ISO 15552 interface, 40mm bore, 520mm stroke, G1/4 port, and mounting accessory. The -S suffix means a piston magnet is present for CS1-B/DS1-B switches. If you need more force, the 50mm bore offers 982N push at 0.5MPa; if less is acceptable, the 32mm bore provides 402N. Note that a plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock, pilot check valve, or SAIL/BSAI variant for load holding. At 520mm stroke, prevent rod bending by guiding the load externally to avoid side-load damage.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X520S
- ✓ 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 SI40X520S FAQ
Yes, the SI40X520S is discontinued. The direct replacement is the SAI40X520S. It is dimensionally interchangeable per ISO 15552, matching the 40mm bore, 520mm stroke, 628N force, G1/4 port, and mounting interface.
The 40mm bore delivers 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, with a 27mm adjustable air cushion at both ends.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X520S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X520S replacement — usually within 7-8 hours.