This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX225, 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 SI50BX225
The AirTAC Airtac SI50 Standard Cylinder SI50BX225 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 225mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX225, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke225 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX225
- 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 SI50BX225
The AirTAC SI50BX225 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 225mm stroke. This SKU features a SUS304 stainless steel rod and lacks a magnet, meaning it cannot accept a position switch.
AirTAC replaced this legacy unit with the SAI50BX225 direct. It shares the exact ISO 15552 mounting interface, G1/4 port, and 30mm cushions. The SAI upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure and longer life. The SAI family also introduces SAIL, SAIF, and BSAI lock variants absent from the SI line.
Airtac SI50 Standard Cylinder SI50BX225 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX225 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX225 |
| Bore size | Ø50 mm |
| Stroke | 225 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 SAI50BX225 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 SAI50BX225 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 SI50BX225
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×225 | 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 SI50BX225 Is Used
Product Diversion
Pushes packages laterally on a belt line using the 982 N push force at 0.5 MPa, with the SUS304 rod resisting moisture washdown.
Film Roll Tensioning
Maintains steady tension on packaging film feeds, benefiting from the 30-800 mm/s speed range and 30mm adjustable end cushions.
Replacing the Airtac SI50 Standard Cylinder SI50BX225 with the SAI50BX225
To replace this SI50BX225, order the SAI50BX225. It drops into existing fixtures via the same ISO 15552 interface, 50mm bore, 225mm stroke, G1/4 port, and M16x1.5 rod thread. Because this specific SKU has no magnet, it cannot support sensing; if you require position feedback, select an SAI equivalent with a magnet and use current AirTAC switches instead of the legacy CS1-B/DS1-B. At 0.5 MPa the 50mm bore provides 982 N push (1374 N at 0.7 MPa), while a neighbouring 63mm bore offers 1559 N. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding consider an external pilot check valve or the SAIL/BSAI lock variants. The 225mm stroke is under the 300mm threshold, so rod bending is minimal, but always guide the load to prevent side-loading.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX225
- ✓ 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 SI50BX225 FAQ
Yes, the SI50BX225 is discontinued. The direct replacement is the SAI50BX225. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 225mm stroke, G1/4 port, and mounting interface, but features an upgraded two Y-shaped element piston seal.
The 50mm bore uses a G1/4 air port. It generates 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, 1767 N at 0.9 MPa, and a theoretical maximum of 200 kgf at 1.0 MPa. Operating pressure is 0.15-1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX225
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX225 replacement — usually within 7-8 hours.