This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X660S, 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 SI50 Standard Cylinder SI50X660S
The AirTAC Airtac SI50 Standard Cylinder SI50X660S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 660mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X660S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke660 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X660S
- 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 SI50 Standard Cylinder SI50X660S
The AirTAC SI50X660S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 660mm stroke. Delivering 982 N push force at 0.5 MPa, it features a G1/4 air port and a magnetic piston for position sensing. AirTAC replaced this legacy unit with the SAI50X660S, a direct replacement retaining the exact ISO 15552 mounting interface, bore, stroke, output force, and port size.
The SAI upgrade introduces a refined piston seal using two Y-shaped one-way elements for lower start-up pressure and extended life. The SAI family also adds SAIL, SAIF, and BSAI lock variants absent in the SI line. This SI50X660S uses legacy CS1-B/DS1-B sensors, while the SAI accepts current AirTAC switches.
Airtac SI50 Standard Cylinder SI50X660S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X660S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X660S |
| Bore size | Ø50 mm |
| Stroke | 660 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| Rod thread | M16×1.5 |
| 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, 30 mm |
| Max standard stroke | Up to 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI50X660S carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø50mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 982 N | 825 N |
| 0.7 MPa | 1374 N | — |
| Max (@1.0 MPa) | 200 kgf | |
The SAI50X660S produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI50 Standard Cylinder SI50X660S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | 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 SI50 Standard Cylinder SI50X660S Is Used
Long-Stroke Diversion
Pushes packages across a 660mm transfer lane using the 982 N thrust at 0.5 MPa, requiring external guide rails to support the extended rod.
Multi-Station Indexing
Shifts a tooling carriage between machining stations, using the magnetic piston and CS1-B/DS1-B sensors to confirm the full 660mm extension.
Replacing the Airtac SI50 Standard Cylinder SI50X660S with the SAI50X660S
To replace the discontinued SI50X660S, order the SAI50X660S. Verify your ISO 15552 mounting fixtures, 50mm bore, 660mm stroke, G1/4 port, and the -S magnet requirement. Because the 660mm stroke creates a long lever arm, use external guides to prevent rod bending and premature seal wear under side loads. For sizing, a 40mm bore yields 628 N push at 0.5 MPa, while a 63mm bore offers 1559 N. This cylinder does not hold load without live air; the cushion only decelerates. For load holding on air loss, use an external pilot check valve or the SAIL/BSAI lock variants. The SAI also offers Viton H seals for high-heat applications.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X660S
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI50 Standard Cylinder SI50X660S FAQ
Yes, the SI50X660S is discontinued. The direct replacement is the SAI50X660S. It shares the identical ISO 15552 mounting interface, 50mm bore, 660mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly while offering an upgraded piston seal.
The 50mm bore features a G1/4 air port and an M16x1.5 rod thread. It generates 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and 1767 N push at 0.9 MPa, with a theoretical maximum of 200 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X660S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X660S replacement — usually within 7-8 hours.