This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX290S, 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 SI40BX290S
The AirTAC Airtac SI40 Standard Cylinder SI40BX290S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 290mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX290S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke290 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX290S
- 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 SI40BX290S
The AirTAC SI40BX290S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 290mm stroke. Delivering 628N push force at 0.5MPa, it features a SUS304 stainless piston rod (-B), a G1/4 port, and a piston magnet (-S) for legacy CS1-B/DS1-B switches. The direct replacement is the SAI40BX290S, matching the bore, stroke, force, and ISO 15552 mounting interface.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. If you need load holding on air loss, note the cushion only decelerates; you must use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants the SI lacked.
Airtac SI40 Standard Cylinder SI40BX290S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX290S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX290S |
| Bore size | Ø40 mm |
| Stroke | 290 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 SAI40BX290S 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 SAI40BX290S 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 SI40BX290S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×290 | 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 SI40BX290S Is Used
Stainless Rod Actuation
Ideal for packaging machines needing corrosion resistance, using the SUS304 rod to push 628N loads over a 290mm travel distance.
Mid-Length Diverting
Handles product diverting on conveyors where a 32kg vertical lift capacity and 290mm stroke provide precise routing without side-load risks.
Replacing the Airtac SI40 Standard Cylinder SI40BX290S with the SAI40BX290S
To replace the SI40BX290S, order the SAI40BX290S. Verify the ISO 15552 mounting interface, 40mm bore, 290mm stroke, G1/4 port, and the -S magnet for current AirTAC switches. The -B code specifies the SUS304 stainless rod for corrosion resistance. Size both ways: a 50mm bore gives 982N push at 0.5MPa, while a 32mm bore yields 402N. At 290mm stroke, use guide rails to prevent rod bending and side-load damage. For dead-load holding, the air cushion only decelerates; add a pilot check valve or explore the SAIL or BSAI lock variants, as standard cylinders drift without live air.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX290S
- ✓ 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 SI40BX290S FAQ
Yes, the SI40BX290S is discontinued. The direct replacement is the SAI40BX290S. It features the same ISO 15552 mounting interface, 40mm bore, 290mm stroke, G1/4 port, and force ratings, fitting existing fixtures perfectly.
The 40mm bore has a G1/4 port. It delivers 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max of 128kgf at 1.0MPa. The speed range is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX290S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX290S replacement — usually within 7-8 hours.