This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X660, 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 SI40X660
The AirTAC Airtac SI40 Standard Cylinder SI40X660 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 660mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X660, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke660 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X660
- 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 SI40X660
The AirTAC SI40X660 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 660mm stroke. Delivering 628N push force at 0.5MPa via a G1/4 port, it is replaced by the SAI40X660. This direct upgrade shares the exact ISO 15552 mounting interface, bore, stroke, force, port and mounting accessories.
The SAI upgrade features a refined piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note this SKU lacks a magnet (-S), so it cannot accept CS1-B/DS1-B sensors. The SAI family also adds SAIL, SAIF and BSAI lock variants the SI lacked.
Airtac SI40 Standard Cylinder SI40X660 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X660 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X660 |
| Bore size | Ø40 mm |
| Stroke | 660 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 SAI40X660 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 SAI40X660 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 SI40X660
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×660 | 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 SI40X660 Is Used
Vertical Lift Gate
Raises a 32kg access gate using the 0.5MPa push force, requiring external guides for the long 660mm stroke.
Component Ejection
Ejects machined parts from a fixture over 660mm, relying on the 27mm adjustable air cushions for smooth stops.
Replacing the Airtac SI40 Standard Cylinder SI40X660 with the SAI40X660
To replace the SI40X660, order the SAI40X660. Confirm the ISO 15552 mounting interface, 40mm bore, 660mm stroke, G1/4 port (PT/G/NPT), and mounting accessory. Because this 660mm stroke exceeds 300mm, use external guides to prevent rod bending and side-load damage. Sizing both ways: the neighboring 32mm bore yields 402N push at 0.5MPa, while the 50mm bore yields 982N. 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. This no-magnet SKU cannot take a sensor.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X660
- ✓ 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 SI40X660 FAQ
Yes, the SI40X660 is discontinued. The direct replacement is the SAI40X660. It shares the same ISO 15552 mounting interface, 40mm bore, 660mm stroke, output force, G1/4 port and mounting accessories, fitting existing fixtures perfectly.
The 40mm bore uses a G1/4 port. Force ratings are: 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. Speed is 30-800mm/s.
Request a Quote for the SAI40X660
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X660 replacement — usually within 7-8 hours.