This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX280, 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 SI50BX280
The AirTAC Airtac SI50 Standard Cylinder SI50BX280 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 SAI50BX280, 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 → SAI50BX280
- 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 SI50BX280
The AirTAC SI50BX280 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 280mm stroke. It delivers 982 N push and 825 N pull at 0.5 MPa through a G1/4 port. The direct replacement is the SAI50BX280, matching the interface, force, and mounting. This non-magnetic SKU cannot accept a sensor.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. It also adds SAIL, SAIF, and BSAI variants the SI lacked. The -B rod option specifies a SUS304 stainless piston rod for corrosion resistance.
Airtac SI50 Standard Cylinder SI50BX280 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX280 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX280 |
| 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 SAI50BX280 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 SAI50BX280 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 SI50BX280
| 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 SI50BX280 Is Used
Package Diverting
Actuates diverting arms on packaging lines, using the 982 N thrust to push cartons reliably at speeds up to 800 mm/s.
Clamp Actuators
Secures mild steel workpieces during machining, relying on the 30mm adjustable air cushions to decelerate the 280mm stroke smoothly.
Replacing the Airtac SI50 Standard Cylinder SI50BX280 with the SAI50BX280
To replace the SI50BX280, order the SAI50BX280. Confirm the ISO 15552 mounting interface, 50mm bore, 280mm stroke, and G1/4 port (PT/G/NPT). This SKU lacks a magnet, so it cannot take a CS1-B/DS1-B sensor; order an -S model if sensing is needed. For sizing, the neighbouring 63mm bore yields 1559 N push at 0.5 MPa, while the 40mm bore yields 628 N. At 280mm stroke, add external guides to prevent rod bending under side loads. A plain cylinder drifts on air loss; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX280
- ✓ 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 SI50BX280 FAQ
Yes, the SI50BX280 is discontinued. The direct replacement is the SAI50BX280, which maintains the same ISO 15552 mounting interface, 50mm bore, 280mm stroke, output force, and G1/4 port.
It has a G1/4 port. The thrust ratings are 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and a theoretical maximum of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX280
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX280 replacement — usually within 7-8 hours.