This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X20, 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 SI50X20
The AirTAC Airtac SI50 Standard Cylinder SI50X20 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 20mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X20, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke20 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X20
- 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 SI50X20
The AirTAC SI50X20 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 20mm stroke. Delivering 982N push and 825N pull at 0.5MPa via a G1/4 port, it is replaced by the direct replacement SAI50X20. This upgrade shares the exact ISO 15552 mounting interface, force, and dimensions. The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure. This non-magnet SKU cannot accept a sensor.
The SAI family adds SAIL, SAIF, and BSAI lock variants the SI lacked. Note that Viton H seals raise operating temps to 150C, and plain cylinders drift without live air.
Airtac SI50 Standard Cylinder SI50X20 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X20 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X20 |
| Bore size | Ø50 mm |
| Stroke | 20 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 SAI50X20 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 SAI50X20 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 SI50X20
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×20 | 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 SI50X20 Is Used
Short-Stroke Clamping
Ideal for holding parts during machining with a 982N push force at 0.5 MPa and a compact 20mm stroke.
Package Diverting
Provides rapid 30-800 mm/s actuation to push light cartons off a production line without overshooting.
Ejector Stations
Delivers a quick 825N pull force to retract ejector pins in small assembly fixtures safely.
Replacing the Airtac SI50 Standard Cylinder SI50X20 with the SAI50X20
To replace the SI50X20, order the SAI50X20. Confirm the ISO 15552 mounting interface, 50mm bore, 20mm stroke, G1/4 port (PT/G/NPT thread), and mounting accessory. This non-magnet SKU cannot take a CS1-B/DS1-B sensor. If you need more force, the 63mm bore yields 1559N push at 0.5MPa; if less is needed, the 40mm bore provides 628N. Remember, 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.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X20
- ✓ 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 SI50X20 FAQ
Yes, the SI50X20 is discontinued. The direct replacement is the SAI50X20, which shares the same ISO 15552 mounting interface, 50mm bore, 20mm stroke, 982N force, and G1/4 port.
It features a G1/4 port and M16x1.5 rod thread. Forces are: 982N push / 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a 200kgf max at 1.0MPa.
Request a Quote for the SAI50X20
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X20 replacement — usually within 7-8 hours.