This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX25, 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 SI40AX25
The AirTAC Airtac SI40 Standard Cylinder SI40AX25 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 SAI40AX25, 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 → SAI40AX25
- 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 SI40AX25
The AirTAC SI40AX25 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 25mm stroke. It delivers 628N push force at 0.5MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI40AX25, a direct upgrade retaining the exact interface, force, and mounting.
The SAI replacement features an upgraded piston seal with two Y-shaped elements for low start-up pressure and long life. Because this specific SKU lacks a magnet (-S), it cannot accept position switches. The -A rod denotes SUS420J2 stainless steel for corrosion resistance.
Airtac SI40 Standard Cylinder SI40AX25 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX25 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX25 |
| 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 SAI40AX25 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 SAI40AX25 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 SI40AX25
| 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 SI40AX25 Is Used
Short-Stroke Clamping
Ideal for compact 25mm clamping tasks in machining fixtures where a 628N push force securely holds aluminum or plastic components.
Package Diverting
Provides rapid 30-800 mm/s actuation for diverting light cartons on packaging lines, with the G1/4 port ensuring fast response.
Corrosive Ejecting
The SUS420J2 stainless rod option excels in damp washdown environments for ejecting washed parts without rod degradation.
Replacing the Airtac SI40 Standard Cylinder SI40AX25 with the SAI40AX25
To replace the SI40AX25, order the SAI40AX25. Confirm the ISO 15552 mounting interface, 40mm bore, 25mm stroke, G1/4 port (PT/G/NPT thread options), and your mounting accessory. This SKU has no magnet, so it cannot support legacy CS1-B/DS1-B sensors; order an -S variant if sensing is needed. The SUS420J2 stainless rod (-A) suits humid environments. Sizing context: a 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N. For load holding on air loss, note the cushion only decelerates; add an external rod lock, pilot check valve, or use the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX25
- ✓ 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 SI40AX25 FAQ
Yes, the SI40AX25 is discontinued. The direct replacement is the SAI40AX25. It is dimensionally interchangeable per ISO 15552, matching the 40mm bore, 25mm stroke, 628N force, G1/4 port, and mounting fixtures.
The 40mm bore uses a G1/4 air port. Force ratings are: 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.
Request a Quote for the SAI40AX25
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX25 replacement — usually within 7-8 hours.