This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X780SN, 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 SI50X780SN
The AirTAC Airtac SI50 Standard Cylinder SI50X780SN is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 780mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X780SN, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke780 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X780SN
- 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 SI50X780SN
The AirTAC SI50X780SN is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 780mm stroke. Delivering 982 N push at 0.5 MPa through a G1/4 port, it is replaced by the SAI50X780SN. This direct successor matches the exact mounting interface, force, and dimensions.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and extended life. It also adds SAIL, SAIF, and BSAI variants absent from the SI line. The NBR seal handles -20 to +70 C, while the magnet supports CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50X780SN Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X780SN |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X780SN |
| Bore size | Ø50 mm |
| Stroke | 780 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 SAI50X780SN 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 SAI50X780SN 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 SI50X780SN
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×780 | 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 SI50X780SN Is Used
Long-Stroke Diversion
Pushes packages across a transfer belt using the 780mm stroke and 982 N force at 0.5 MPa.
Automated Door Actuation
Opens large machinery guard doors over a 780mm travel distance, guided externally to prevent rod bending.
Replacing the Airtac SI50 Standard Cylinder SI50X780SN with the SAI50X780SN
To replace the SI50X780SN, order the SAI50X780SN direct, confirming the ISO 15552 interface, 50mm bore, 780mm stroke, G1/4 port, and mounting. The SAI uses current AirTAC switches for the magnet. For sizing, the 40mm bore yields 628 N push, while the 63mm bore gives 1559 N at 0.5 MPa. Note that 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. At 780mm, prevent rod bending by using external guides to manage side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X780SN
- ✓ 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 SI50X780SN FAQ
Yes, the SI50X780SN is discontinued. The direct replacement is the SAI50X780SN, which maintains the same ISO 15552 mounting interface, 50mm bore, 780mm stroke, force, and G1/4 port.
It features a G1/4 port and delivers 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and a theoretical max of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X780SN
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X780SN replacement — usually within 7-8 hours.