This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX55, 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 SI40AX55
The AirTAC SI40 Standard Cylinder SI40AX55 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 55mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40AX55, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke55 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40AX55
- 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 SI40AX55
The AirTAC SI40AX55 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 55mm stroke, delivering 628N push force at 0.5MPa. AirTAC replaced it with the SAI40AX55, a direct upgrade retaining the same G1/4 port, M12x1.25 rod thread, and mounting interface.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This SKU has no magnet (-S) and cannot take a sensor. The SUS420J2 stainless rod resists corrosion, and a Viton H seal option raises heat resistance to 150C.
Airtac SI40 Standard Cylinder SI40AX55 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX55 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX55 |
| Bore size | Ø40 mm |
| Stroke | 55 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 SAI40AX55 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 SAI40AX55 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 SI40AX55
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×55 | 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 SI40AX55 Is Used
Compact Clamping
Ideal for securing mid-weight aluminum or steel workpieces on machining fixtures where a 55mm stroke provides rapid actuation.
Package Diverting
Drives short-stroke diverter arms on packaging lines, using the 628N push force at 0.5MPa to redirect cartons efficiently.
Gate Actuation
Operates lightweight access gates or material flow stops in distribution centers, benefiting from the SUS420J2 stainless rod.
Replacing the Airtac SI40 Standard Cylinder SI40AX55 with the SAI40AX55
To replace the SI40AX55, order the SAI40AX55. Verify your ISO 15552 mounting fixtures, G1/4 port, and M12x1.25 thread. Because this SKU lacks a magnet, it cannot accept CS1-B/DS1-B switches; add the -S suffix if you need position sensing. Sizing both ways: a 32mm bore yields 402N at 0.5MPa, while a 50mm bore yields 982N. Note that a plain cylinder drifts on air loss; for load holding, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX55
- ✓ 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 SI40AX55 FAQ
Yes, the SI40AX55 is discontinued. The direct replacement is the SAI40AX55. It shares the exact same ISO 15552 mounting interface, 40mm bore, 55mm stroke, output force, and G1/4 port, fitting directly into your existing fixtures.
This double-acting cylinder features a G1/4 air port and M12x1.25 rod thread. It delivers 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. Speed is 30-800mm/s.
Request a Quote for the SAI40AX55
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX55 replacement — usually within 7-8 hours.