This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX300S, 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 SI50AX300S
The AirTAC Airtac SI50 Standard Cylinder SI50AX300S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 300mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX300S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke300 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX300S
- 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 SI50AX300S
The AirTAC SI50AX300S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 300mm stroke, and a SUS420J2 stainless piston rod. It delivers 982N push force at 0.5MPa via a G1/4 port. The direct replacement is the SAI50AX300S, matching the exact bore, stroke, force, port, and ISO 15552 mounting interface for seamless fixture integration.
The SAI upgrade features an improved piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The original SI utilized CS1-B/DS1-B switches via its built-in magnet, while the SAI family uses current AirTAC sensors.
Airtac SI50 Standard Cylinder SI50AX300S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX300S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX300S |
| Bore size | Ø50 mm |
| Stroke | 300 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 SAI50AX300S 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 SAI50AX300S 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 SI50AX300S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×300 | 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 SI50AX300S Is Used
Diverting Gate Actuation
Provides the 982N push force needed to pivot heavy conveyor sorting gates, with the 300mm stroke offering full travel clearance for product redirection.
Vertical Pallet Stops
Ideal for lifting or stopping pallets up to 50kg on low-friction roller conveyors, utilizing the SUS420J2 stainless rod for humid washdown environments.
Long-Reach Part Ejection
Ejects machined components from deep fixtures, where the 300mm stroke is required to clear the work envelope completely before the next cycle.
Replacing the Airtac SI50 Standard Cylinder SI50AX300S with the SAI50AX300S
To replace the SI50AX300S, order the SAI50AX300S. Confirm the ISO 15552 mounting interface, 50mm bore, 300mm stroke, G1/4 port (PT/G/NPT thread), and your specific mounting accessory. The -S magnet and -A SUS420J2 rod are retained. For sizing alternatives, a 40mm bore yields 628N push at 0.5MPa, while a 63mm bore provides 1559N. Because this is a 300mm stroke, use external guides to prevent rod-bending and premature seal wear from side loads. A plain cylinder does not hold load without live air; the cushion only decelerates. For load holding, use an external pilot check valve or explore the SAIL or BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX300S
- ✓ 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 SI50AX300S FAQ
Yes, the SI50AX300S is discontinued. The direct replacement is the SAI50AX300S. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 300mm stroke, 982N force, G1/4 port, and mounting interface.
This 50mm bore cylinder uses a G1/4 air port. The force output is 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical maximum of 200kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX300S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX300S replacement — usually within 7-8 hours.