This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX270, 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 SI50BX270
The AirTAC Airtac SI50 Standard Cylinder SI50BX270 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 SAI50BX270, 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 → SAI50BX270
- 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 SI50BX270
The AirTAC SI50BX270 is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 270 mm stroke. It delivers 982 N push force at 0.5 MPa via a G1/4 port. The direct replacement is the SAI50BX270, which matches the exact interface, bore, stroke, force, port and mounting hardware. The SAI upgrade features an improved piston seal with two Y-shaped one-way elements for low start-up pressure and extended life.
This specific SKU includes a SUS304 stainless steel piston rod (-B) for corrosion resistance but lacks a magnet, meaning it cannot accept position sensors like the legacy CS1-B or DS1-B switches. Note that a plain cylinder drifts on air loss; for load holding, consider the SAIL or BSAI lock variants.
Airtac SI50 Standard Cylinder SI50BX270 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX270 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX270 |
| 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 SAI50BX270 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 SAI50BX270 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 SI50BX270
| 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 SI50BX270 Is Used
Diverting Gates
Actuates routing flaps on package conveyors where the 982 N push force at 0.5 MPa easily overcomes friction and the 270 mm stroke provides full gate travel.
Stopper Arms
Controls pallet stops in material handling lines, with the SUS304 stainless rod offering corrosion resistance in humid or washdown environments.
Replacing the Airtac SI50 Standard Cylinder SI50BX270 with the SAI50BX270
To replace the discontinued SI50BX270, order the SAI50BX270 direct equivalent. Verify your ISO 15552 mounting interface (LB, FA, TC, etc.), the 270 mm stroke, and the G1/4 port. Because this SKU has no magnet (-S), it cannot support switches; if sensing is needed, select an SAI50X270S and use current AirTAC switches. The 270 mm stroke is within the 1200 mm standard limit, but at this length you should check side loads and use a guide to prevent rod bending. Sizing both ways: the 50 mm bore yields 982 N push at 0.5 MPa, while a neighbouring 63 mm bore offers 1559 N. If you need to hold a load without live air, the cushion only decelerates; use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX270
- ✓ 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 SI50BX270 FAQ
Yes, the AirTAC SI50BX270 is discontinued. The direct replacement is the SAI50BX270. It is dimensionally interchangeable per ISO 15552, retaining the same 50 mm bore, 270 mm stroke, G1/4 port, and mounting fixtures.
The 50 mm bore provides a push force of 982 N and a pull force of 825 N at 0.5 MPa. At 0.7 MPa it pushes 1374 N, and at 0.9 MPa it pushes 1767 N. The theoretical maximum force is 200 kgf at 1.0 MPa, with an operating speed of 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX270
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