This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X280SFA, 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 SI50X280SFA
The AirTAC Airtac SI50 Standard Cylinder SI50X280SFA is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 280mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X280SFA, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke280 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X280SFA
- 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 SI50X280SFA
The AirTAC SI50X280SFA is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 280 mm stroke. It delivers 982 N push force at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50X280SFA, a direct sharing the same interface, force, and FA flange mounting.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family also adds SAIL, SAIF, and BSAI lock variants the SI lacked. Your -S magnet works with legacy CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50X280SFA Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X280SFA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X280SFA |
| Bore size | Ø50 mm |
| Stroke | 280 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 SAI50X280SFA 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 SAI50X280SFA 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 SI50X280SFA
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×280 | 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 SI50X280SFA Is Used
Mid-Force Diverting
Drives diverter arms on packaging lines, using the 982 N push force to reliably redirect heavy cartons at speed.
Vertical Lift Gates
Raises and lowers 50 kg access gates on machinery enclosures, benefiting from the adjustable cushion at stroke ends.
Clamp Actuation
Secures workpieces during machining operations, providing stable holding via the FA flange mount under 0.5 MPa.
Replacing the Airtac SI50 Standard Cylinder SI50X280SFA with the SAI50X280SFA
To replace the SI50X280SFA, order the SAI50X280SFA. Confirm the ISO 15552 interface, 50 mm bore, 280 mm stroke, G1/4 port, and FA flange. The -S magnet enables CS1-B/DS1-B sensors (SAI uses current switches). If you need more force, the 63 mm bore gives 1559 N [email protected]; if less is needed, the 40 mm gives 628 N. At 280 mm stroke, use a guide to prevent rod bending and side-load wear. A plain cylinder drifts on air loss; for load holding, use an external rod lock, pilot check valve, or SAIL/BSAI variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X280SFA
- ✓ 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 SI50X280SFA FAQ
Yes, the SI50X280SFA is discontinued. The direct replacement is the SAI50X280SFA. It is dimensionally interchangeable per ISO 15552, retaining the same 50 mm bore, 280 mm stroke, G1/4 port, and FA mounting interface.
It features a G1/4 air port. The thrust is 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and 1767 N push at 0.9 MPa. The theoretical maximum force is 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X280SFA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X280SFA replacement — usually within 7-8 hours.