This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX350S, 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 SI40AX350S
The AirTAC Airtac SI40 Standard Cylinder SI40AX350S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 350mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40AX350S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke350 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40AX350S
- 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 SI40AX350S
The AirTAC SI40AX350S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 350mm stroke. It delivers 628N push force at 0.5MPa via a G1/4 port. The direct replacement is the SAI40AX350S, matching the bore, stroke, force, port and ISO 15552 mounting interface for a seamless fixture swap.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. This -A variant uses a SUS420J2 stainless rod, and the -S magnet works with legacy CS1-B/DS1-B sensors.
Airtac SI40 Standard Cylinder SI40AX350S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX350S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX350S |
| Bore size | Ø40 mm |
| Stroke | 350 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 SAI40AX350S 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 SAI40AX350S 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 SI40AX350S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×350 | 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 SI40AX350S Is Used
Material Diverting
Actuates routing gates on packaging lines, utilizing the 350mm stroke to shift products between parallel conveyor belts smoothly.
Parts Pressing
Provides a steady 628N push force to seat bearings or pins into housings without marring delicate component surfaces.
Replacing the Airtac SI40 Standard Cylinder SI40AX350S with the SAI40AX350S
To replace the SI40AX350S, order the SAI40AX350S. Verify the ISO 15552 interface, 40mm bore, 350mm stroke, G1/4 port, and SUS420J2 stainless rod (-A). The -S magnet enables current AirTAC switches (legacy used CS1-B/DS1-B). At 0.5MPa it yields 628N push and 528N pull; if undersized, the 50mm bore offers 982N push. A 350mm stroke requires external guides to prevent rod bending under side loads. For load holding on air loss, use an external pilot check valve or the SAIL/BSAI lock variant, as cushions only decelerate.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX350S
- ✓ 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 SI40AX350S FAQ
Yes, the SI40AX350S is discontinued. The direct replacement is the SAI40AX350S. It shares the exact same ISO 15552 mounting interface, 40mm bore, 350mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly.
This 40mm bore cylinder uses a G1/4 air port. It generates 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical maximum of 128kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40AX350S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX350S replacement — usually within 7-8 hours.