This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX900S, 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 SI50BX900S
The AirTAC Airtac SI50 Standard Cylinder SI50BX900S 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 SAI50BX900S, 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 → SAI50BX900S
- 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 SI50BX900S
The AirTAC SI50BX900S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 900mm stroke, SUS304 stainless rod (-B) and piston magnet (-S). Delivering 982N push at 0.5MPa, it is replaced by the SAI50BX900S. This direct upgrade shares the exact G1/4 port, M16x1.5 thread and ISO 15552 mounting dimensions. The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The original -S magnet supports legacy CS1-B/DS1-B sensors, while SAI uses current switches.
For higher temperatures, Viton H seals raise the limit to 150C. The SAI family adds SAIL, SAIF and BSAI lock variants. Note: air cushions only decelerate; they do not hold loads.
Airtac SI50 Standard Cylinder SI50BX900S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX900S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX900S |
| 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 SAI50BX900S 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 SAI50BX900S 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 SI50BX900S
| 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 SI50BX900S Is Used
Long-Reach Diverting
Actuates diverter arms across wide conveyor belts where the 900mm stroke and 982N force at 0.5MPa are required to push parcels.
Vertical Material Lift
Hoists light pallets or totes up to 50kg in automated storage systems, relying on the SUS304 rod for corrosion resistance.
Extended-Stroke Ejection
Ejects machined parts from deep fixtures, using adjustable end cushions to decelerate the 900mm travel smoothly.
Replacing the Airtac SI50 Standard Cylinder SI50BX900S with the SAI50BX900S
To replace the SI50BX900S, order SAI50BX900S to get the exact ISO 15552 interface, 50mm bore, 900mm stroke, G1/4 port, and SUS304 rod. Confirm your mounting accessory (LB, FA, TC, etc.) and magnet (-S). The 50mm bore yields 982N push / 825N pull at 0.5MPa; neighbouring bores are 40mm (628N) and 63mm (1559N). A 900mm stroke demands external guides to prevent rod bending under side-loads. Plain cylinders drift without air; for load holding use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX900S
- ✓ 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 SI50BX900S FAQ
Yes, the AirTAC SI50BX900S is discontinued. The direct replacement is the SAI50BX900S. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 900mm stroke, G1/4 port, and mounting interface to fit existing fixtures.
The 50mm bore features a G1/4 port and M16x1.5 rod thread. At 0.5MPa it provides 982N push and 825N pull. At 0.7MPa push is 1374N, and 1767N at 0.9MPa. The theoretical maximum force is 200kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX900S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX900S replacement — usually within 7-8 hours.