This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X350SH, 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 SI40X350SH
The AirTAC Airtac SI40 Standard Cylinder SI40X350SH 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 SAI40X350SH, 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 → SAI40X350SH
- 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 SI40X350SH
The AirTAC SI40X350SH is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 350mm stroke. Delivering 628 N push force at 0.5 MPa via a G1/4 port, it is replaced by the SAI40X350SH. This direct upgrade shares the exact ISO 15552 mounting interface, bore, stroke, force, port and accessories. The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The -H suffix denotes a Viton H seal, extending the operating temperature to 0-150 C.
The built-in magnet (-S) supports legacy CS1-B/DS1-B switches, while the SAI replacement uses current AirTAC switches. The SAI family also introduces SAIL, SAIF and BSAI lock variants absent in the SI line.
Airtac SI40 Standard Cylinder SI40X350SH Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X350SH |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X350SH |
| 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 SAI40X350SH 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 SAI40X350SH 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 SI40X350SH
| 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 SI40X350SH Is Used
High-Temp Diverting
Actuating diverter arms on hot material conveyor lines where the Viton H seal withstands 0-150 C ambient heat.
Long-Stroke Transfers
Moving components between stations over a 350mm reach, requiring external guides to prevent rod bending.
Replacing the Airtac SI40 Standard Cylinder SI40X350SH with the SAI40X350SH
To replace the SI40X350SH, order the SAI40X350SH. Verify the ISO 15552 mounting interface, 40mm bore, 350mm stroke, G1/4 port (PT/G/NPT), M12x1.25 rod thread and the magnet (-S). If you need higher force, the 50mm bore offers 982 N push at 0.5 MPa; if lower force is acceptable, the 32mm bore provides 402 N. For the 350mm stroke, use external guides to prevent rod bending and side-load wear. A plain cylinder does not hold load on air loss; the 27mm adjustable cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X350SH
- ✓ 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 SI40X350SH FAQ
Yes, the SI40X350SH is discontinued. The direct replacement is the SAI40X350SH. It shares the same ISO 15552 mounting interface, 40mm bore, 350mm stroke, output force, G1/4 port and mounting accessories, fitting existing fixtures perfectly.
The SI40X350SH provides 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. Operating speed is 30-800 mm/s. It features a G1/4 port and a 27mm adjustable air cushion at both ends.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X350SH
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X350SH replacement — usually within 7-8 hours.