This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX270S, 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 SI50BX270S
The AirTAC SI50 Standard Cylinder SI50BX270S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 270mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX270S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke270 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX270S
- 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 SI50BX270S
The AirTAC SI50BX270S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 270mm stroke, and a SUS304 stainless piston rod. Delivering 982N push force at 0.5MPa via a G1/4 port, it is replaced by the SAI50BX270S. This direct upgrade shares the exact ISO 15552 mounting interface, bore, stroke, and force. The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The -S magnet supports legacy CS1-B/DS1-B sensors.
The SAI family also introduces SAIL, SAIF, and BSAI lock variants absent in the SI line. Note that a plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external rod lock or the SAIL/BSAI variant.
Airtac SI50 Standard Cylinder SI50BX270S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX270S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX270S |
| Bore size | Ø50 mm |
| Stroke | 270 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 SAI50BX270S 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 SAI50BX270S 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 SI50BX270S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×270 | 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 SI50BX270S Is Used
Stainless Rod Clamping
Ideal for packaging machinery requiring corrosion resistance, using the SUS304 rod to actuate clamping arms with a 982N push force at 0.5 MPa.
Mid-Stroke Diversion
Deployed on material handling lines to push products at 270mm stroke, benefiting from the 30-800 mm/s speed range for rapid sorting.
Replacing the Airtac SI50 Standard Cylinder SI50BX270S with the SAI50BX270S
To replace the SI50BX270S, order the SAI50BX270S. Confirm the ISO 15552 mounting interface, 50mm bore, 270mm stroke, G1/4 port (PT/G/NPT thread options), and your mounting accessory. The -S magnet enables CS1-B/DS1-B sensors, though the SAI replacement uses current AirTAC switches. The -B rod is SUS304 stainless steel, ideal for corrosion resistance compared to the standard carbon steel. Sizing both ways: the 50mm bore yields 982N push at 0.5MPa (1374N at 0.7MPa); if less force is needed, a 40mm bore provides 628N. Because the 270mm stroke exceeds 300mm? No, at 270mm side-load risks are moderate, but always guide the load to prevent rod bending. A plain cylinder does not hold load without live air; the cushion only decelerates. For secure holding, specify the SAIL lock or BSAI clamp-lock variant, or add an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX270S
- ✓ 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 SI50BX270S FAQ
Yes, the SI50BX270S is discontinued. The direct replacement is the SAI50BX270S. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 270mm stroke, G1/4 port, and mounting interface. You simply order the SAI equivalent.
The bore is 50mm with a G1/4 air port. Force ratings are: 982N push and 825N pull at 0.5 MPa, 1374N push at 0.7 MPa, 1767N push at 0.9 MPa, and a theoretical max of 200 kgf at 1.0 MPa. The rod is Ø20mm with an M16x1.5 thread.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX270S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX270S replacement — usually within 7-8 hours.