This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX280, 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 SI50AX280
The AirTAC Airtac SI50 Standard Cylinder SI50AX280 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 SAI50AX280, 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 → SAI50AX280
- 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 SI50AX280
The AirTAC SI50AX280 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 280mm stroke. It delivers 982 N push force at 0.5 MPa and features a G1/4 air port with an M16x1.5 rod thread. The direct replacement is the SAI50AX280, which matches the exact mounting interface, output force, and dimensions.
This SKU uses a SUS420J2 stainless piston rod for corrosion resistance but lacks a magnet, meaning it cannot accept position switches. The SAI upgrade introduces a two Y-shaped one-way piston seal for lower start-up pressure.
Airtac SI50 Standard Cylinder SI50AX280 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX280 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX280 |
| 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 SAI50AX280 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 SAI50AX280 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 SI50AX280
| 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 SI50AX280 Is Used
Package Diverting
Actuates routing gates on packaging lines where the 982 N push force at 0.5 MPa easily handles moderate carton weights.
Stainless Rod Tooling
The SUS420J2 rod option suits light machining or washdown fixtures requiring resistance to surface corrosion over 280mm travel.
Replacing the Airtac SI50 Standard Cylinder SI50AX280 with the SAI50AX280
To replace the SI50AX280, order the SAI50AX280. Verify the ISO 15552 mounting interface, 50mm bore, 280mm stroke, G1/4 port (PT/G/NPT thread options), and your specific mounting accessory. Because this is a no-magnet SKU, it cannot support legacy CS1-B/DS1-B sensors; order an -S SAI variant if sensing is required. For sizing alternatives, a 40mm bore yields 628 N push at 0.5 MPa, while a 63mm bore provides 1559 N. At 280mm stroke, ensure adequate guide support to prevent rod bending and side-load wear. Note that a plain cylinder drifts on air loss; for load holding, use an external pilot check valve, rod lock, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX280
- ✓ 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 SI50AX280 FAQ
Yes, the AirTAC SI50AX280 is discontinued. The direct replacement is the SAI50AX280. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 280mm stroke, G1/4 port, and mounting interface.
This double-acting cylinder uses a G1/4 air port and an M16x1.5 rod thread. The thrust ratings are: 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, 1767 N push at 0.9 MPa, and a theoretical maximum of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX280
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX280 replacement — usually within 7-8 hours.