This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX35, 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 SI40AX35
The AirTAC Airtac SI40 Standard Cylinder SI40AX35 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 SAI40AX35, 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 → SAI40AX35
- 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 SI40AX35
The AirTAC SI40AX35 is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 35 mm stroke. It delivers 628 N push and 528 N pull at 0.5 MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI40AX35, a direct sharing the exact ISO 15552 mounting interface, bore, stroke, force and port size.
The SAI upgrade features a redesigned piston seal using two Y-shaped one-way elements for lower start-up pressure and longer life. This specific SKU lacks a magnet, so it cannot accept a position switch. The SUS420J2 stainless rod resists corrosion.
Airtac SI40 Standard Cylinder SI40AX35 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX35 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX35 |
| 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 SAI40AX35 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 SAI40AX35 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 SI40AX35
| 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 SI40AX35 Is Used
Clamping Fixtures
Secures workpieces during machining with 628 N of push force at 0.5 MPa, providing reliable holding without deforming parts.
Package Diverting
Short 35 mm stroke actuates diverters or gates to route small to medium goods along material handling lines at high speeds.
Stopper Gates
Acts as a pneumatic stop in conveyor zones, using its SUS420J2 stainless rod to withstand minor environmental moisture.
Replacing the Airtac SI40 Standard Cylinder SI40AX35 with the SAI40AX35
To replace the SI40AX35, order the SAI40AX35 and verify your ISO 15552 mounting interface, 40 mm bore, 35 mm stroke, and G1/4 port. Confirm the rod-end thread is M12x1.25 and select PT, G, or NPT thread options to match your fittings. Because this SKU has no -S magnet, it cannot support legacy CS1-B/DS1-B sensors; choose an SAI variant with a magnet if you need position detection. If your application needs to hold a load on air loss, note that a plain cylinder drifts when centered—the cushion only decelerates—so add an external rod lock, a pilot check valve, or specify the SAIL or BSAI lock variant. If you need more force, the 50 mm bore offers 982 N push at 0.5 MPa; if you need less, the 32 mm bore provides 402 N.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX35
- ✓ 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 SI40AX35 FAQ
Yes, the SI40AX35 is discontinued. The direct replacement is the SAI40AX35. It shares the same ISO 15552 mounting interface, 40 mm bore, 35 mm stroke, output force, and G1/4 port, so it drops directly into existing fixtures.
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 maximum force of 128 kgf at 1.0 MPa.
Request a Quote for the SAI40AX35
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX35 replacement — usually within 7-8 hours.