This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X440S, 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 SI40X440S
The AirTAC Airtac SI40 Standard Cylinder SI40X440S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 440mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X440S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke440 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X440S
- 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 SI40X440S
The AirTAC SI40X440S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 440mm stroke. Delivering 628N push and 528N pull at 0.5MPa via a G1/4 port, it is replaced by the SAI40X440S. This direct upgrade keeps the exact ISO 15552 mounting interface, bore, stroke and output force.
The SAI features an upgraded piston seal with two Y-shaped elements for low start-up pressure and long life. The SAI family also adds SAIL, SAIF and BSAI lock variants the SI lacked. Your -S magnet works with legacy CS1-B/DS1-B sensors, while SAI uses current AirTAC switches.
Airtac SI40 Standard Cylinder SI40X440S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X440S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X440S |
| Bore size | Ø40 mm |
| Stroke | 440 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 SAI40X440S 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 SAI40X440S 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 SI40X440S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×440 | 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 SI40X440S Is Used
Pneumatic Ejection
Pushes completed parts out of machining fixtures, relying on adjustable end cushions to decelerate the rod smoothly over the long travel.
Replacing the Airtac SI40 Standard Cylinder SI40X440S with the SAI40X440S
To replace the SI40X440S, order the SAI40X440S. It drops directly into existing fixtures via the ISO 15552 mounting interface, matching the 40mm bore, 440mm stroke, M12x1.25 rod thread and G1/4 port. If you need more force, the neighbouring 50mm bore yields 982N push at 0.5MPa; if less is acceptable, the 32mm bore provides 402N. Because the 440mm stroke is long, use an external guide to prevent rod bending and side-load damage. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding consider the SAIL or BSAI lock variants, or an external pilot check valve. Retain your -S magnet for position sensing.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X440S
- ✓ 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 SI40X440S FAQ
Yes, the SI40X440S is discontinued. The direct replacement is the SAI40X440S. It shares the identical ISO 15552 mounting interface, 40mm bore, 440mm stroke, output force and G1/4 port, fitting existing fixtures perfectly.
This double-acting cylinder uses a G1/4 port and delivers 628N push / 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max of 128kgf at 1.0MPa. It operates at 30-800mm/s with a 27mm adjustable cushion.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X440S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X440S replacement — usually within 7-8 hours.