This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX20S, 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 SI40AX20S
The AirTAC Airtac SI40 Standard Cylinder SI40AX20S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 20mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40AX20S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke20 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40AX20S
- 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 SI40AX20S
The AirTAC SI40AX20S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore, 20 mm stroke, and an SUS420J2 stainless steel rod. Delivering 628 N push force at 0.5 MPa, it is replaced by the SAI40AX20S. This direct upgrade shares the exact ISO 15552 mounting interface, G1/4 port, and M12x1.25 thread, fitting existing fixtures seamlessly.
The SAI features an upgraded piston seal with two Y-shaped elements for low start-up pressure and long life. Note that plain cylinders drift without air; use a pilot check valve or the SAIL lock variant for load holding.
Airtac SI40 Standard Cylinder SI40AX20S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX20S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX20S |
| Bore size | Ø40 mm |
| Stroke | 20 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 SAI40AX20S 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 SAI40AX20S 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 SI40AX20S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×20 | 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 SI40AX20S Is Used
Stainless Rod Clamping
Short 20 mm stroke with SUS420J2 rod excels at moisture-resistant clamping tasks in machining cells.
Transfer Line Diverters
Provides 628 N push at 0.5 MPa to actuate compact routing gates on 40 mm bore packaging conveyors.
Replacing the Airtac SI40 Standard Cylinder SI40AX20S with the SAI40AX20S
To replace the SI40AX20S, order the SAI40AX20S, confirming the ISO 15552 mounting interface, 40 mm bore, 20 mm stroke, G1/4 port, and magnet for CS1-B/DS1-B switches. The SAI family adds SAIL, SAIF, and BSAI lock variants the SI lacked. If sizing up, a 50 mm bore offers 982 N push at 0.5 MPa; if sizing down, a 32 mm bore provides 402 N. Remember, a plain cylinder does not hold load on air loss—use an external rod lock or pilot check valve for vertical holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX20S
- ✓ 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 SI40AX20S FAQ
Yes, the SI40AX20S is discontinued. The direct replacement is the SAI40AX20S, which shares the identical ISO 15552 mounting interface, bore, stroke, force, and G1/4 port.
It features a G1/4 port and delivers 628 N push / 528 N pull at 0.5 MPa, 879 N push at 0.7 MPa, 1130 N push at 0.9 MPa, and a theoretical max of 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40AX20S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX20S replacement — usually within 7-8 hours.