This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX45S, 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 SI50AX45S
The AirTAC SI50 Standard Cylinder SI50AX45S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 45mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX45S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke45 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX45S
- 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 SI50AX45S
The AirTAC SI50AX45S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 45mm stroke, and a SUS420J2 stainless steel rod. It delivers 982 N of push force at 0.5 MPa. AirTAC replaced this legacy unit with the SAI50AX45S, a direct replacement matching the exact ISO 15552 mounting interface, bore, stroke, G1/4 port, and output force.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Because the -S magnet is present, this cylinder supports legacy CS1-B/DS1-B sensors, while the SAI family uses current AirTAC switches.
Airtac SI50 Standard Cylinder SI50AX45S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX45S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX45S |
| Bore size | Ø50 mm |
| Stroke | 45 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 SAI50AX45S 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 SAI50AX45S 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 SI50AX45S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×45 | 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 SI50AX45S Is Used
Stainless Rod Actuation
Ideal for packaging machinery where the SUS420J2 stainless piston rod resists washdown corrosion while providing 982 N of push force.
Short-Stroke Diverting
The 45mm stroke is perfectly suited for actuating diverter gates or pushers on a 50 kg payload conveyor line.
Material Handling Stops
Deploys pneumatic stop gates in sorting systems, utilizing the G1/4 port and ISO 15552 profile for easy fixture integration.
Replacing the Airtac SI50 Standard Cylinder SI50AX45S with the SAI50AX45S
To replace the SI50AX45S, order the SAI50AX45S. Verify your ISO 15552 mounting interface, the 45mm stroke, the G1/4 port, and your specific mounting accessory (LB, FA, TC, etc.). The -S magnet and -A SUS420J2 stainless rod carry over directly. If you need to size up or down, the neighboring bores are 40mm (628 N push @0.5 MPa) and 63mm (1559 N push @0.5 MPa). Note that a plain ISO 15552 cylinder does not hold load on air loss; the air cushion only decelerates near stroke end. For load holding, use an external rod lock, a pilot check valve, or explore the SAIL (air-released lock) and BSAI (clamp-lock) variants. The SAIF variant offers a built-in 4M valve for bores 32-100.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX45S
- ✓ 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 SI50AX45S FAQ
Yes, the SI50AX45S is discontinued. The direct replacement is the SAI50AX45S. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 45mm stroke, G1/4 port, and mounting interface.
The 50mm bore features a G1/4 air port and delivers 982 N push / 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, 1767 N push at 0.9 MPa, and a theoretical max of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX45S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX45S replacement — usually within 7-8 hours.