This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX35S, 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 SI40AX35S
The AirTAC Airtac SI40 Standard Cylinder SI40AX35S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 35mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40AX35S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke35 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40AX35S
- 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 SI40AX35S
The AirTAC SI40AX35S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 35mm stroke. It delivers 628N push force at 0.5MPa through a G1/4 port. The direct replacement is the SAI40AX35S, matching the bore, stroke, force, port, and ISO 15552 mounting interface exactly.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. This specific SI40AX35S unit includes the -A SUS420J2 stainless rod and -S magnet for legacy CS1-B/DS1-B sensors.
Airtac SI40 Standard Cylinder SI40AX35S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX35S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX35S |
| Bore size | Ø40 mm |
| Stroke | 35 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 SAI40AX35S 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 SAI40AX35S 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 SI40AX35S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×35 | 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 SI40AX35S Is Used
Compact Clamping
Applies 628N of push force at 0.5MPa to secure mid-size workpieces during machining operations.
Short Stroke Diverter
Uses the 35mm stroke to push small packages on a line, benefiting from the 30-800mm/s speed range.
Stainless Rod Ejection
The SUS420J2 rod option provides corrosion resistance for ejecting parts in humid storage environments.
Replacing the Airtac SI40 Standard Cylinder SI40AX35S with the SAI40AX35S
To replace this SI cylinder, order the SAI40AX35S. Verify your ISO 15552 mounting interface, 40mm bore, 35mm stroke, G1/4 port, and the -S magnet for current AirTAC switches. This unit has the -A SUS420J2 stainless rod for corrosion resistance; confirm if you need this over standard carbon steel. Sizing both ways: a 32mm bore offers 402N push at 0.5MPa, while a 50mm bore offers 982N. If you need load holding on air loss, note that a plain cylinder drifts and the cushion only decelerates; use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX35S
- ✓ 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 SI40AX35S FAQ
Yes, the SI40AX35S is discontinued. The direct replacement is the SAI40AX35S. It matches the ISO 15552 mounting interface, 40mm bore, 35mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly.
It features 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.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40AX35S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX35S replacement — usually within 7-8 hours.