This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X780S, 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 SI50X780S
The AirTAC Airtac SI50 Standard Cylinder SI50X780S 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 SAI50X780S, 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 → SAI50X780S
- 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 SI50X780S
The AirTAC SI50X780S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 780mm stroke. Delivering 982 N push at 0.5 MPa via a G1/4 port, it is replaced by the SAI50X780S. This direct successor matches the exact ISO 15552 mounting interface, bore, stroke, force and port size.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life. It also adds SAIL, SAIF and BSAI variants absent from the SI line. The SI50X780S uses CS1-B/DS1-B sensors; the SAI uses current AirTAC switches.
Airtac SI50 Standard Cylinder SI50X780S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X780S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X780S |
| 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 SAI50X780S 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 SAI50X780S 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 SI50X780S
| 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 SI50X780S Is Used
Long-Stroke Diversion
Pushes packages across a 780mm conveyor lane transfer using the 982 N push force at 0.5 MPa.
Press Ejection
Ejects formed parts from a press bed, relying on the 30mm adjustable air cushions to decelerate at stroke end.
Replacing the Airtac SI50 Standard Cylinder SI50X780S with the SAI50X780S
To replace the SI50X780S, order the SAI50X780S. Verify the ISO 15552 mounting interface, the 50mm bore, 780mm stroke, G1/4 port (PT/G/NPT threads), M16x1.5 rod thread, and the -S magnet for position sensing. If you need more force, the 63mm bore offers 1559 N push at 0.5 MPa; if less is required, the 40mm bore provides 628 N. Because the 780mm stroke is long, use an external guide to prevent rod bending and side-load damage. A plain cylinder drifts without air and its cushion only decelerates; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X780S
- ✓ 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 SI50X780S FAQ
Yes, the SI50X780S is discontinued. The direct replacement is the SAI50X780S. It shares the same ISO 15552 mounting interface, 50mm bore, 780mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly.
The 50mm bore uses a G1/4 port. At 0.5 MPa it provides 982 N push and 825 N pull. At 0.7 MPa push is 1374 N, and the theoretical maximum force is 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X780S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X780S replacement — usually within 7-8 hours.