This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40BX650, 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 SI40BX650
The AirTAC Airtac SI40 Standard Cylinder SI40BX650 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 650mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40BX650, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke650 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40BX650
- 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 SI40BX650
The AirTAC SI40BX650 is a discontinued double-acting ISO 15552 profile cylinder featuring a 40 mm bore, 650 mm stroke, and a SUS304 stainless steel piston rod. Generating 628 N push force at 0.5 MPa, it is replaced by the direct replacement SAI40BX650. This upgrade shares the exact ISO 15552 mounting interface, G1/4 port, and 128 kgf max force, fitting existing fixtures seamlessly.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. Because this specific SKU lacks a magnet (-S), it cannot accept position switches.
Airtac SI40 Standard Cylinder SI40BX650 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40BX650 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40BX650 |
| Bore size | Ø40 mm |
| Stroke | 650 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 SAI40BX650 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 SAI40BX650 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 SI40BX650
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×650 | 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 SI40BX650 Is Used
Long-Stroke Diversion
Pushes packages across transfer lines with its 650 mm reach, relying on external guides to prevent side-load bending on the extended rod.
Stainless Material Handling
Operates sorting gates in humid washdown areas using the SUS304 rod option, providing 628 N of push force at 0.5 MPa.
Vertical Lowering
Lowers light fixtures safely; note that a pilot check valve is required to hold the load, as the cushion only decelerates at stroke end.
Replacing the Airtac SI40 Standard Cylinder SI40BX650 with the SAI40BX650
To replace the SI40BX650, order the SAI40BX650. Verify your ISO 15552 mounting accessory (LB, FA, TC, etc.), the 650 mm stroke, and the G1/4 port. This SKU has no magnet and cannot take a sensor; if sensing is needed, select an SAI40X650S model and use current AirTAC switches. For sizing, the 40 mm bore yields 628 N push at 0.5 MPa; if undersized, the 50 mm bore offers 982 N. Note: at 650 mm, prevent rod bending by guiding the load externally. A plain cylinder drifts on air loss; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40BX650
- ✓ 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 SI40BX650 FAQ
Yes, the SI40BX650 is discontinued. The direct replacement is the SAI40BX650. It shares the exact ISO 15552 mounting interface, 40 mm bore, 650 mm stroke, G1/4 port, and force ratings, fitting existing fixtures perfectly.
The 40 mm bore has a G1/4 port, M12x1.25 rod thread, 27 mm cushions, and 30-800 mm/s speed. Force ratings are: 628 N push / 528 N pull at 0.5 MPa, 879 N push at 0.7 MPa, 1130 N at 0.9 MPa, and a 128 kgf max at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40BX650
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40BX650 replacement — usually within 7-8 hours.