This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX325S, 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 SI40AX325S
The AirTAC Airtac SI40 Standard Cylinder SI40AX325S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 325mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40AX325S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke325 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40AX325S
- 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 SI40AX325S
The AirTAC SI40AX325S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 325mm stroke. It delivers 628 N push force at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI40AX325S, a direct upgrade retaining the exact interface, M12x1.25 thread, and 128 kgf max output.
The SAI successor features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This specific SKU includes a SUS420J2 stainless rod and a magnet for CS1-B/DS1-B sensors.
Airtac SI40 Standard Cylinder SI40AX325S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX325S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX325S |
| Bore size | Ø40 mm |
| Stroke | 325 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 SAI40AX325S 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 SAI40AX325S 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 SI40AX325S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×325 | 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 SI40AX325S Is Used
Package Diverting
Pushes cartons on packaging lines using the 628 N push force, with the 325mm stroke clearing diverter lanes.
Clamp Actuation
Secures medium workpieces during machining, leveraging the 32 kg safe vertical lift capacity.
Gate Operation
Indexes sorting gates in distribution hubs, relying on the SUS420J2 stainless rod for moisture resistance.
Replacing the Airtac SI40 Standard Cylinder SI40AX325S with the SAI40AX325S
To replace the SI40AX325S, order the SAI40AX325S direct: it matches the ISO 15552 mounting dimensions, 40mm bore, 325mm stroke, G1/4 port, and -S magnet. Retain your existing mounting hardware and CS1-B/DS1-B sensors, though the SAI family uses current AirTAC switches. If you need more force, the 50mm bore offers 982 N push at 0.5 MPa; if less is acceptable, the 32mm bore provides 402 N. Because the stroke is 325mm, use an external guide to prevent rod-bending side loads. Note that a plain cylinder drifts on air loss—the cushion only decelerates. For load holding, specify the SAIL lock or BSAI clamp-lock variant, or add a pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX325S
- ✓ 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 SI40AX325S FAQ
Yes, the SI40AX325S is discontinued. The direct replacement is the SAI40AX325S. It is dimensionally interchangeable per ISO 15552, keeping the same 40mm bore, 325mm stroke, G1/4 port, and mounting interface.
This double-acting cylinder uses a G1/4 air port. It generates 628 N push and 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 SAI40AX325S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX325S replacement — usually within 7-8 hours.