This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X25, 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 SI40X25
The AirTAC Airtac SI40 Standard Cylinder SI40X25 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 25mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X25, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke25 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X25
- 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 SI40X25
The AirTAC SI40X25 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 25mm stroke, delivering 628N push force at 0.5MPa via a G1/4 port. The direct replacement is the SAI40X25, matching the bore, stroke, force, port and ISO 15552 mounting interface exactly.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and long life. Note this specific SKU lacks a magnet, so it cannot accept CS1-B/DS1-B sensors.
Airtac SI40 Standard Cylinder SI40X25 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X25 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X25 |
| Bore size | Ø40 mm |
| Stroke | 25 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 SAI40X25 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 SAI40X25 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 SI40X25
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×25 | 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 SI40X25 Is Used
Short-Stroke Clamping
Ideal for compact 32kg vertical clamping arms where a 25mm stroke provides rapid, precise positioning without excessive rod overhang.
Part Ejection
Delivers a fast 628N push to eject small machined components from fixtures, operating efficiently at speeds up to 800mm/s.
Replacing the Airtac SI40 Standard Cylinder SI40X25 with the SAI40X25
To replace the SI40X25, order the SAI40X25 and verify your ISO 15552 mounting fixture, G1/4 port, and M12x1.25 rod thread. Because this SKU has no -S magnet, it cannot support position sensing; if detection is needed, switch to an SAI40X25S. For sizing alternatives, a 32mm bore yields 402N push at 0.5MPa, while a 50mm bore provides 982N. Remember the air cushion only decelerates at end-of-stroke; it does not hold load. For static holding against air loss, use an external pilot check valve, rod lock, or the SAIL/BSAI lock variants. The 25mm stroke is very short, so side-load risks are minimal.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X25
- ✓ 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 SI40X25 FAQ
Yes, the AirTAC SI40X25 is discontinued. The direct replacement is the SAI40X25. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 25mm stroke, 628N force, G1/4 port, and mounting interface.
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 max force is 128kgf at 1.0MPa. Operating speed ranges from 30-800mm/s, and it uses a G1/4 air port.
Request a Quote for the SAI40X25
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X25 replacement — usually within 7-8 hours.