This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX240S, 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 SI40AX240S
The AirTAC Airtac SI40 Standard Cylinder SI40AX240S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 240mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40AX240S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke240 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40AX240S
- 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 SI40AX240S
The AirTAC SI40AX240S is a discontinued double-acting ISO 15552 profile cylinder featuring a 40mm bore, 240mm stroke, and a SUS420J2 stainless steel piston rod. Delivering 628N push force at 0.5MPa, it is replaced by the SAI40AX240S. This direct upgrade matches the G1/4 port, M12x1.25 thread, and ISO 15552 mounting interface.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The SI40AX240S includes a magnet for legacy CS1-B/DS1-B sensors; note that a plain cylinder drifts on air loss, so use a pilot check valve or SAIL lock variant for holding.
Airtac SI40 Standard Cylinder SI40AX240S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX240S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX240S |
| Bore size | Ø40 mm |
| Stroke | 240 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 SAI40AX240S 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 SAI40AX240S 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 SI40AX240S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×240 | 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 SI40AX240S Is Used
Stainless Rod Duty
The SUS420J2 rod excels in mildly corrosive spot-welding or washdown cells where a standard carbon rod would pit.
Replacing the Airtac SI40 Standard Cylinder SI40AX240S with the SAI40AX240S
To replace the SI40AX240S, order the SAI40AX240S. Confirm the ISO 15552 mounting interface, 40mm bore, 240mm stroke, G1/4 port (PT/G/NPT), and your mounting accessory. The -S magnet enables CS1-B/DS1-B sensors, while the SAI uses current AirTAC switches. The -A rod is SUS420J2 stainless steel. At 0.5MPa it yields 628N push; the neighbouring 50mm bore provides 982N if you need more force. For 240mm strokes, guide external rods to prevent side-load bending. A plain cylinder does not hold load without air; use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants for secure holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX240S
- ✓ 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 SI40AX240S FAQ
Yes, the SI40AX240S is discontinued. The direct replacement is the SAI40AX240S. It shares the same ISO 15552 mounting interface, 40mm bore, 240mm stroke, force, G1/4 port, and M12x1.25 thread, fitting existing fixtures perfectly.
The 40mm bore provides 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max of 128kgf at 1.0MPa. Operating speed is 30-800mm/s, with a 27mm adjustable air cushion at both ends.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40AX240S
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