This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X780S, 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 SI40 Standard Cylinder SI40X780S
The AirTAC Airtac SI40 Standard Cylinder SI40X780S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 780mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X780S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke780 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X780S
- 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 SI40 Standard Cylinder SI40X780S
The AirTAC SI40X780S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 780mm stroke. Delivering 628N push force at 0.5MPa through a G1/4 port, it is replaced by the SAI40X780S. This direct successor matches the exact mounting interface, bore, stroke, output force, and accessories, fitting existing fixtures perfectly.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The SI family lacked lock variants, but the SAI line adds SAIL, SAIF, and BSAI options. This SI40X780S includes a magnet for CS1-B/DS1-B sensors.
Airtac SI40 Standard Cylinder SI40X780S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X780S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X780S |
| Bore size | Ø40 mm |
| Stroke | 780 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| Rod thread | M12×1.25 |
| 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, 27 mm |
| Max standard stroke | Up to 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI40X780S carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 kgf | |
The SAI40X780S produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI40 Standard Cylinder SI40X780S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | 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 SI40 Standard Cylinder SI40X780S Is Used
Long-Stroke Diversion
Pushes packages across transfer lines with a 780mm reach, utilizing the 628N force to overcome guide friction on extended strokes.
Automated Press Ejection
Ejects formed parts from machinery, relying on adjustable 27mm air cushions to decelerate the piston at stroke ends.
Replacing the Airtac SI40 Standard Cylinder SI40X780S with the SAI40X780S
To replace the SI40X780S, order the SAI40X780S. Confirm the ISO 15552 mounting interface, 40mm bore, 780mm stroke, G1/4 port (PT/G/NPT thread options), and mounting accessory. The -S suffix means a magnet is present for CS1-B/DS1-B switches; the SAI replacement uses current AirTAC switches. For sizing, the 40mm bore yields 628N push at 0.5MPa; dropping to a 32mm bore gives 402N, while a 50mm bore offers 982N. Because this is a 780mm stroke, use external guides to prevent rod bending and side-load wear. A plain cylinder drifts on air loss; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X780S
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI40 Standard Cylinder SI40X780S FAQ
Yes, the AirTAC SI40X780S is discontinued. The direct replacement is the SAI40X780S. It is dimensionally interchangeable per ISO 15552, matching the 40mm bore, 780mm stroke, G1/4 port, and mounting interface for a seamless fixture swap.
The 40mm bore cylinder has a G1/4 air port. At 0.5MPa it provides 628N push and 528N pull force. At 0.7MPa push is 879N, and at 0.9MPa it is 1130N. The theoretical maximum force is 128kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X780S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X780S replacement — usually within 7-8 hours.