This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX900, 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 SI50AX900
The AirTAC SI50 Standard Cylinder SI50AX900 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 SAI50AX900, 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 → SAI50AX900
- 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 SI50AX900
The AirTAC SI50AX900 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 900mm stroke. It delivers 982N push and 825N pull at 0.5MPa via a G1/4 port. The direct replacement is the SAI50AX900, which shares the exact ISO 15552 mounting interface, output force, and accessories. The SAI features an upgraded piston seal using two Y-shaped one-way elements for low start-up pressure and long life. This -A variant uses a SUS420J2 stainless piston rod for corrosion resistance. Because it lacks the -S magnet, this SKU cannot take a sensor.
The SAI family also introduces variants the SI lacked, such as the SAIL air-released lock and BSAI clamp-lock for load holding. Note that a 900mm stroke requires external guides to prevent rod bending under side loads.
Airtac SI50 Standard Cylinder SI50AX900 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX900 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX900 |
| 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 SAI50AX900 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 SAI50AX900 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 SI50AX900
| 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 SI50AX900 Is Used
Long-Stroke Diversion
Pushes packages across a wide conveyor belt sorting line using the full 900mm stroke extension.
Stainless Rod Washdown
Actuates a washdown gate or flap utilizing the SUS420J2 stainless rod for corrosion resistance.
Replacing the Airtac SI50 Standard Cylinder SI50AX900 with the SAI50AX900
To replace the SI50AX900, order the SAI50AX900. Verify the ISO 15552 mounting interface, 50mm bore, 900mm stroke, G1/4 port, and your specific mounting accessory (LB, FA, TC, etc.). This SKU has no -S magnet, so it cannot accept CS1-B or DS1-B sensors; if sensing is needed, select an SAI50X900S. If you need more force, the neighbouring 63mm bore yields 1559N push at 0.5MPa; if less is required, the 40mm bore gives 628N. For load holding on air loss, a plain cylinder drifts—use an external pilot check valve or the SAIL/BSAI lock variants. Finally, at 900mm, use external guides to prevent rod-bending side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX900
- ✓ 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 SI50AX900 FAQ
Yes, the SI50AX900 is discontinued. The direct replacement is the SAI50AX900. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 900mm stroke, G1/4 port, and mounting interface.
The 50mm bore has a G1/4 port. Force ratings are: 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical max of 200kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX900
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX900 replacement — usually within 7-8 hours.