This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X50S, 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 SI50X50S
The AirTAC Airtac SI50 Standard Cylinder SI50X50S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 50mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X50S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke50 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X50S
- 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 SI50X50S
The AirTAC SI50X50S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 50mm stroke. Delivering 982N push force at 0.5MPa via a G1/4 port, it is replaced by the SAI50X50S. This direct upgrade matches the exact ISO 15552 mounting interface, bore, stroke, force and port.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SAI family adds SAIL, SAIF and BSAI lock variants the SI lacked. This -S SKU has a piston magnet for CS1-B/DS1-B sensors; the SAI uses current AirTAC switches.
Airtac SI50 Standard Cylinder SI50X50S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X50S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X50S |
| Bore size | Ø50 mm |
| Stroke | 50 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 SAI50X50S 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 SAI50X50S 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 SI50X50S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×50 | 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 SI50X50S Is Used
Clamping Fixtures
Ideal for mid-force clamping of workpieces in machining centers, utilizing the 982N push force at 0.5MPa for rigid holding.
Package Diverting
Short 50mm stroke provides rapid actuation for diverting or sorting medium-weight packages on material handling lines.
Pallet Stops
Reliable 50mm extension acts as a pneumatic stop gate for pallets up to 50kg, matching the computed vertical lift capacity.
Replacing the Airtac SI50 Standard Cylinder SI50X50S with the SAI50X50S
To replace the SI50X50S, order the SAI50X50S. Confirm the ISO 15552 mounting interface, G1/4 port (PT/G/NPT), M16x1.5 rod thread, and your mounting accessory (LB, FA, TC, etc.). The -S denotes a piston magnet for legacy CS1-B/DS1-B sensors. Sizing both ways: if you need more force, the 63mm bore yields 1559N push at 0.5MPa; if less, the 40mm bore yields 628N. A plain cylinder drifts on air loss—the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. Stroke is under 300mm, so rod-bending side-load risks are minimal.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X50S
- ✓ 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 SI50X50S FAQ
Yes, the SI50X50S is discontinued. The direct replacement is the SAI50X50S. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 50mm stroke, G1/4 port, output force, and mounting interface.
The bore is 50mm with a G1/4 air port. Force ratings are: 982N push / 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical max of 200kgf at 1.0MPa. Operating speed is 30-800mm/s.
Request a Quote for the SAI50X50S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X50S replacement — usually within 7-8 hours.