This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X320S, 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 SI40X320S
The AirTAC Airtac SI40 Standard Cylinder SI40X320S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 320mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X320S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke320 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X320S
- 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 SI40X320S
The AirTAC SI40X320S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 320 mm stroke. It delivers 628 N push force at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI40X320S, a direct sharing the same ISO 15552 mounting interface, stroke, force, and port size.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This SI-SKU includes a piston magnet for legacy CS1-B/DS1-B sensors, while the SAI uses current AirTAC switches.
Airtac SI40 Standard Cylinder SI40X320S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X320S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X320S |
| Bore size | Ø40 mm |
| Stroke | 320 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 SAI40X320S 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 SAI40X320S 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 SI40X320S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×320 | 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 SI40X320S Is Used
Package Diverting
Actuates routing gates on packaging lines, using the 320 mm stroke to clear standard totes safely.
Component Ejection
Pushes machined parts out of a fixture, relying on adjustable 27 mm cushions to soften end impacts.
Replacing the Airtac SI40 Standard Cylinder SI40X320S with the SAI40X320S
To replace this SI40X320S, order the SAI40X320S. Confirm your ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/4 port thread (PT/G/NPT), and the M12x1.25 rod thread. Because the stroke is 320 mm, add external guides to prevent rod bending and side-load wear. If you need more force, the neighboring 50 mm bore gives 982 N push at 0.5 MPa; if less is needed, the 32 mm bore provides 402 N. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X320S
- ✓ 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 SI40X320S FAQ
Yes, the SI40X320S is discontinued. The direct replacement is the SAI40X320S. It is dimensionally interchangeable per ISO 15552, keeping the same 40 mm bore, 320 mm stroke, 628 N force, G1/4 port, and mounting interface.
This double-acting cylinder has a G1/4 port. It generates 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 SAI40X320S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X320S replacement — usually within 7-8 hours.