This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX290S, 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 SI50AX290S
The AirTAC Airtac SI50 Standard Cylinder SI50AX290S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 290mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX290S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke290 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX290S
- 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 SI50AX290S
The AirTAC SI50AX290S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 290mm stroke, and a SUS420J2 stainless steel piston rod. It delivers 982 N push force at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50AX290S, a direct sharing the exact ISO 15552 mounting interface, bore, stroke, and output force.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This -S SKU includes a piston magnet for legacy CS1-B/DS1-B sensors, while the SAI family adds SAIL, SAIF, and BSAI lock variants the SI lacked.
Airtac SI50 Standard Cylinder SI50AX290S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX290S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX290S |
| Bore size | Ø50 mm |
| Stroke | 290 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 SAI50AX290S 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 SAI50AX290S 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 SI50AX290S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×290 | 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 SI50AX290S Is Used
Stainless Rod Actuation
Leverages the SUS420J2 rod for corrosion resistance in washdown machining cells, pushing 982 N at 0.5 MPa.
Transfer Line Diverting
Uses the G1/4 port and adjustable 30mm cushions to decelerate diverting arms smoothly without end-of-stroke impact.
Replacing the Airtac SI50 Standard Cylinder SI50AX290S with the SAI50AX290S
To replace the SI50AX290S, order the SAI50AX290S. Confirm the ISO 15552 interface, 50mm bore, 290mm stroke, G1/4 port (PT/G/NPT thread), and SUS420J2 rod. The -S magnet works with legacy CS1-B/DS1-B switches; the SAI uses current AirTAC sensors. Sizing both ways: a 40mm bore yields 628 N push @0.5 MPa, while a 63mm bore yields 1559 N. At 290mm stroke, use guide rails to prevent rod bending and side-load damage. A plain cylinder drifts on air loss; cushions only decelerate. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX290S
- ✓ 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 SI50AX290S FAQ
Yes, the SI50AX290S is discontinued. The direct replacement is the SAI50AX290S. It shares the same ISO 15552 mounting interface, 50mm bore, 290mm stroke, force, G1/4 port, and SUS420J2 rod, fitting existing fixtures perfectly.
The G1/4 port feeds a 20mm rod delivering 982 N push and 825 N pull at 0.5 MPa. At 0.7 MPa push is 1374 N, and 1767 N at 0.9 MPa. The theoretical max is 200 kgf at 1.0 MPa, with adjustable 30mm cushions both ends.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX290S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX290S replacement — usually within 7-8 hours.