This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX325S, 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 SI50AX325S
The AirTAC Airtac SI50 Standard Cylinder SI50AX325S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 325mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX325S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke325 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX325S
- 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 SI50AX325S
The AirTAC SI50AX325S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 325mm stroke, and a SUS420J2 stainless steel rod. Delivering 982 N push force at 0.5 MPa, it is replaced by the SAI50AX325S. This direct upgrade shares the exact ISO 15552 mounting interface, G1/4 port, and M16x1.5 thread, fitting existing fixtures perfectly.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The original -S magnet supports CS1-B/DS1-B sensors, while the SAI family adds SAIL, SAIF, and BSAI variants. Note that plain cylinders drift on air loss; use an external rod lock for holding.
Airtac SI50 Standard Cylinder SI50AX325S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX325S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX325S |
| Bore size | Ø50 mm |
| Stroke | 325 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 SAI50AX325S 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 SAI50AX325S 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 SI50AX325S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×325 | 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 SI50AX325S Is Used
Material Diversion
Actuates routing gates on packaging lines, utilizing the 982 N push force to deflect heavy cartons reliably at speed.
Stainless Rod Handling
Suitable for mildly corrosive environments thanks to the SUS420J2 stainless rod, moving parts in and out of treatment zones.
Replacing the Airtac SI50 Standard Cylinder SI50AX325S with the SAI50AX325S
To replace the SI50AX325S, order the SAI50AX325S, confirming the ISO 15552 interface, 50mm bore, 325mm stroke, G1/4 port, and -S magnet. The -A rod is SUS420J2 stainless steel, and the -S magnet works with legacy CS1-B/DS1-B switches (the SAI uses current AirTAC switches). Sizing both ways: a 40mm bore gives 628 N push at 0.5 MPa, while a 63mm bore yields 1559 N. If you need load holding on air loss, the cushion only decelerates; use an external pilot check valve or the SAIL/BSAI lock variant. Because 325mm exceeds 300mm, add external guides to prevent rod bending under side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX325S
- ✓ 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 SI50AX325S FAQ
Yes, the SI50AX325S is discontinued. The direct replacement is the SAI50AX325S. It is dimensionally interchangeable per ISO 15552, keeping the same 50mm bore, 325mm stroke, G1/4 port, and mounting interface.
It features a G1/4 air port. The force 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 max of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX325S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX325S replacement — usually within 7-8 hours.