This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X340, 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 SI40X340
The AirTAC Airtac SI40 Standard Cylinder SI40X340 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 340mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X340, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke340 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X340
- 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 SI40X340
The AirTAC SI40X340 is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 340 mm stroke, delivering 628 N push force at 0.5 MPa through its G1/4 port. AirTAC replaced this legacy unit with the SAI40X340, a direct upgrade retaining the exact interface, bore, stroke, output force, and mounting dimensions.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Because this specific SKU lacks the -S magnet, it cannot accept position sensors like the legacy CS1-B or DS1-B switches.
Airtac SI40 Standard Cylinder SI40X340 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X340 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X340 |
| Bore size | Ø40 mm |
| Stroke | 340 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 SAI40X340 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 SAI40X340 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 SI40X340
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×340 | 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 SI40X340 Is Used
Package Diverting
Ideal for pushing medium-weight cartons off a main conveyor line, utilizing the 628 N push force at 0.5 MPa for reliable lateral transfers.
Pallet Stopper Gate
Acts as a pneumatic stop gate in pallet flow systems, where the 340 mm stroke provides ample reach to block or release incoming loads.
Replacing the Airtac SI40 Standard Cylinder SI40X340 with the SAI40X340
To replace the discontinued SI40X340, order the SAI40X340, confirming the ISO 15552 mounting interface, 40 mm bore, 340 mm stroke, and G1/4 port (available in PT, G, or NPT). This non-magnetic SKU cannot support switches, so if sensing is required, specify an -S magnet on the SAI. For sizing alternatives, a 32 mm bore yields 402 N push at 0.5 MPa, while a 50 mm bore provides 982 N. Note that a plain cylinder drifts on air loss—the cushion only decelerates—so use an external pilot check valve or the SAIL/BSAI lock variant for load holding. At 340 mm, prevent rod bending by guiding the load externally to avoid side-load damage.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X340
- ✓ 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 SI40X340 FAQ
Yes, the AirTAC SI40X340 is discontinued. The direct replacement is the SAI40X340. It is dimensionally interchangeable per ISO 15552, matching the 40 mm bore, 340 mm stroke, G1/4 port, and mounting interface, but adds an upgraded two Y-shaped element piston seal for longer life.
The 40 mm bore features a G1/4 air port and a 16 mm rod. 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. Operating speed is 30-800 mm/s.
Request a Quote for the SAI40X340
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X340 replacement — usually within 7-8 hours.