This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX325, 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 SI40AX325
The AirTAC Airtac SI40 Standard Cylinder SI40AX325 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 SAI40AX325, 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 → SAI40AX325
- 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 SI40AX325
The AirTAC SI40AX325 is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 325 mm stroke. It features a SUS420J2 stainless steel piston rod (A option) and delivers 628 N push force at 0.5 MPa via its G1/4 port. The direct replacement is the SAI40AX325, which matches the original ISO 15552 mounting interface, bore, stroke, output force, and port size exactly.
Because this SKU lacks the -S magnet suffix, it cannot accept a position sensor. The SAI upgrade introduces a two Y-shaped one-way piston seal for lower start-up pressure and longer life. Note that plain cylinders drift without live air; for held loads consider the SAIL lock or BSAI clamp-lock variants.
Airtac SI40 Standard Cylinder SI40AX325 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX325 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX325 |
| 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 SAI40AX325 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 SAI40AX325 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 SI40AX325
| 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 SI40AX325 Is Used
Diverting Gates
Actuates routing flaps on packaging lines, using the 628 N push force to reliably pivot heavy cardboard flows.
Lift Stations
Raises lightweight jigs or workpieces; the 325 mm stroke provides ample elevation while external guides absorb side loads.
Pallet Stops
Deploys mechanical stops at conveyor ends, securely halting pallets with its SUS420J2 stainless rod resisting moisture.
Replacing the Airtac SI40 Standard Cylinder SI40AX325 with the SAI40AX325
To replace the SI40AX325, order the SAI40AX325. It is a direct per the ISO 15552 mounting interface, retaining the 40 mm bore, 325 mm stroke, G1/4 port, M12x1.25 rod thread, and SUS420J2 stainless rod. Confirm your mounting accessory (LB, FA, TC, etc.) and thread standard (PT, G, NPT). Since this SKU has no -S magnet, you cannot mount legacy CS1-B/DS1-B sensors; order an -S version if sensing is needed. At 0.5 MPa it yields 628 N push / 528 N pull; if undersized, the neighboring 50 mm bore gives 982 N push. A 325 mm stroke invites side-load and rod-bending risks—use external guides to prevent jamming. The air cushion (27 mm) only decelerates; it does not hold load on air loss, so add a pilot check valve or explore the SAIL/BSAI lock variants for static holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX325
- ✓ 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 SI40AX325 FAQ
Yes, the SI40AX325 is discontinued. The direct replacement is the SAI40AX325. It matches the ISO 15552 mounting interface, 40 mm bore, 325 mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly.
This double-acting cylinder has a G1/4 air port. It delivers 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 SAI40AX325
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX325 replacement — usually within 7-8 hours.