This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X900S, 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 SI50X900S
The AirTAC Airtac SI50 Standard Cylinder SI50X900S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 900mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X900S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke900 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X900S
- 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 SI50X900S
The AirTAC SI50X900S is a discontinued double-acting ISO 15552 profile cylinder featuring a 50mm bore, 900mm stroke, and a G1/4 port. Delivering 982 N push force at 0.5 MPa, it is replaced by the SAI50X900S. This direct upgrade matches the exact ISO 15552 mounting interface, bore, stroke, force, and port size for existing fixtures.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SI50X900S includes a magnet for CS1-B/DS1-B switches, while the SAI family adds SAIL, SAIF, and BSAI lock variants.
Airtac SI50 Standard Cylinder SI50X900S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X900S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X900S |
| Bore size | Ø50 mm |
| Stroke | 900 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 SAI50X900S 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 SAI50X900S 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 SI50X900S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×900 | 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 SI50X900S Is Used
Long-Stroke Diversion
Pushes packages across transfer lines with 982 N push at 0.5 MPa, utilizing the 900mm stroke for wide conveyor routing.
Pneumatic Press Ejection
Ejects parts from press beds using the 1767 N thrust available at 0.9 MPa, taking advantage of the adjustable 30mm cushions.
Replacing the Airtac SI50 Standard Cylinder SI50X900S with the SAI50X900S
To replace the SI50X900S, order the SAI50X900S. Confirm the ISO 15552 interface, 50mm bore, 900mm stroke, G1/4 port (PT/G/NPT), and mounting accessory. The built-in magnet (-S) works with legacy CS1-B/DS1-B sensors, though the SAI replacement uses current AirTAC switches. For sizing both ways, a 40mm bore yields 628 N push at 0.5 MPa, while a 63mm bore yields 1559 N. A plain cylinder does not hold load without live air; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. At 900mm stroke, prevent rod bending by using external guides to manage side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X900S
- ✓ 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 SI50X900S FAQ
Yes, the SI50X900S is discontinued. The direct replacement is the SAI50X900S. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 900mm stroke, 982 N force, and G1/4 port.
The SI50X900S operates at 30-800 mm/s. Force ratings are: 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, 1767 N push at 0.9 MPa, and a theoretical max of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X900S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X900S replacement — usually within 7-8 hours.