This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X40, 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 SI40X40
The AirTAC Airtac SI40 Standard Cylinder SI40X40 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 40mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X40, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke40 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X40
- 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 SI40X40
The AirTAC SI40X40 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 40mm stroke, delivering 628N push force at 0.5MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI40X40. This current-production direct maintains the exact ISO 15552 mounting interface, bore, stroke, output force, and port size, fitting existing fixtures perfectly.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note this specific SKU lacks a magnet (-S), so it cannot accept CS1-B or DS1-B sensors.
Airtac SI40 Standard Cylinder SI40X40 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X40 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X40 |
| Bore size | Ø40 mm |
| Stroke | 40 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 SAI40X40 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 SAI40X40 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 SI40X40
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×40 | 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 SI40X40 Is Used
Small Part Ejection
Provides reliable 628N push force at 0.5MPa to eject machined components from fixtures in automated machining centers.
Package Diverting
Actuates diverter arms on packaging lines where a compact 40mm bore and 40mm stroke fit tight conveyor clearances.
Clamp Actuation
Drives short-stroke clamping mechanisms for light-duty woodworking or assembly jigs requiring rapid 30-800mm/s cycling.
Replacing the Airtac SI40 Standard Cylinder SI40X40 with the SAI40X40
To replace the SI40X40, order the SAI40X40 and verify your ISO 15552 mounting accessory (LB, FA, TC, etc.), G1/4 port thread (PT, G, or NPT), and 40mm stroke. When sizing, note the 40mm bore yields 628N push at 0.5MPa; if less force is needed, the 32mm bore offers 402N, or step up to the 50mm bore for 982N. Because this plain cylinder lacks a magnet, it cannot host position sensors. Also, remember it will not hold a load without live air—the cushion only decelerates. For load holding, consider an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X40
- ✓ 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 SI40X40 FAQ
Yes, the SI40X40 is discontinued. The direct replacement is the SAI40X40, which shares the same ISO 15552 mounting interface, 40mm bore, 40mm stroke, force, and G1/4 port.
The 40mm bore features a G1/4 port and delivers 628N push / 528N pull at 0.5MPa, 879N push at 0.7MPa, and a theoretical max of 128kgf at 1.0MPa.
Request a Quote for the SAI40X40
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X40 replacement — usually within 7-8 hours.