This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX550, 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 SI50BX550
The AirTAC Airtac SI50 Standard Cylinder SI50BX550 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 550mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX550, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke550 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX550
- 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 SI50BX550
The AirTAC SI50BX550 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 550mm stroke. Delivering 982N push force at 0.5MPa, it features a SUS304 stainless piston rod, M16x1.5 thread, and a G1/4 port. This SKU lacks a magnet and cannot accept a sensor.
Order the direct replacement SAI50BX550: identical ISO 15552 mounting, force, and port. The SAI upgrades the piston seal to two Y-shaped elements for low start-up pressure. For load holding, the cushion only decelerates; use SAIL or BSAI lock variants.
Airtac SI50 Standard Cylinder SI50BX550 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX550 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX550 |
| Bore size | Ø50 mm |
| Stroke | 550 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 SAI50BX550 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 SAI50BX550 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 SI50BX550
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×550 | 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 SI50BX550 Is Used
Long-Stroke Diversion
Pushes packages across a 550mm transfer gap with 982N force, relying on external guides to prevent rod bending during the extended travel.
Stainless Rod Washdown
Actuates testing probes in humid environments using the SUS304 rod option, while the G1/4 port manages 30-800mm/s speeds.
Replacing the Airtac SI50 Standard Cylinder SI50BX550 with the SAI50BX550
To replace the SI50BX550, order the SAI50BX550. Verify the ISO 15552 interface, 50mm bore, 550mm stroke, G1/4 port (PT/G/NPT), and SUS304 rod. This SKU has no magnet, so it cannot take CS1-B/DS1-B sensors. At 0.5MPa it yields 982N push; sizing down, a 40mm bore gives 628N. For 550mm strokes, use external guides to prevent rod bending. The cushion only decelerates; for load holding use an external rod lock, pilot check valve, or SAIL/BSAI variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX550
- ✓ 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 SI50BX550 FAQ
Yes, the SI50BX550 is discontinued. The direct replacement is the SAI50BX550. It shares the identical ISO 15552 mounting interface, 50mm bore, 550mm stroke, G1/4 port, and force, fitting existing fixtures directly.
It features a G1/4 port. The 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 SAI50BX550
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX550 replacement — usually within 7-8 hours.