This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX550, 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 SI50AX550
The AirTAC Airtac SI50 Standard Cylinder SI50AX550 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 550mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX550, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke550 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX550
- 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 SI50AX550
The AirTAC SI50AX550 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 550mm stroke. Built with an extruded aluminum barrel and adjustable air cushions, it delivers 982 N push force at 0.5 MPa. The direct replacement is the SAI50AX550, retaining the same interface, bore, stroke, force, and G1/4 port.
This SKU features a SUS420J2 stainless steel rod (-A) for corrosion resistance. The SAI upgrade utilizes two Y-shaped one-way piston seals for low start-up pressure. Note this version lacks a magnet, so it cannot accept CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50AX550 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX550 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX550 |
| Bore size | Ø50 mm |
| Stroke | 550 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 SAI50AX550 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 SAI50AX550 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 SI50AX550
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×550 | 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 SI50AX550 Is Used
Long-Stroke Diversion
Drives 550mm routing gates on packaging conveyors where the 982 N push force easily overcomes panel friction.
Stainless Rod Actuation
Acts as a corrosion-resistant pusher (-A rod) in humid washdown environments, moving parts between processing cells.
Replacing the Airtac SI50 Standard Cylinder SI50AX550 with the SAI50AX550
To replace the SI50AX550, order the SAI50AX550. Confirm the ISO 15552 mounting interface, the 50mm bore, 550mm stroke, G1/4 port (PT/G/NPT thread options), and your specific mounting accessory (LB, FA, TC, etc.). Because this is a non-magnet SKU, it cannot support position sensing; add the -S suffix if switches are needed. For sizing, the 50mm bore yields 982 N push at 0.5 MPa; drop to 40mm for 628 N or step up to 63mm for 1559 N. The 550mm stroke requires external guides to prevent rod bending and side-load wear. Plain cylinders drift without live air; for load holding, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX550
- ✓ 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 SI50AX550 FAQ
Yes, the SI50AX550 is discontinued. The direct replacement is the SAI50AX550. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 550mm stroke, output force, G1/4 port, and mounting fixtures.
The G1/4 port feeds a 50mm bore that yields 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and 1767 N at 0.9 MPa. The theoretical maximum force is 200 kgf at 1.0 MPa. It operates at 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX550
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX550 replacement — usually within 7-8 hours.