This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X650S, 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 SI40X650S
The AirTAC Airtac SI40 Standard Cylinder SI40X650S 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 SAI40X650S, 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 → SAI40X650S
- 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 SI40X650S
The AirTAC SI40X650S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 650mm stroke. Delivering 628N push at 0.5MPa through a G1/4 port, it is replaced by the SAI40X650S. This direct upgrade shares the exact ISO 15552 mounting interface, M12x1.25 rod thread and force ratings. The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life.
The SAI family adds SAIL, SAIF and BSAI variants absent in the SI line. This -S SKU includes a piston magnet for legacy CS1-B/DS1-B sensors; SAI uses current AirTAC switches. A Viton H seal option raises the -20 to 70C range to 150C.
Airtac SI40 Standard Cylinder SI40X650S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X650S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X650S |
| 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 SAI40X650S 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 SAI40X650S 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 SI40X650S
| 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 SI40X650S Is Used
Component Ejection
Ejects machined parts from fixtures using the 628N thrust at 0.5MPa, handling long traverse distances.
Replacing the Airtac SI40 Standard Cylinder SI40X650S with the SAI40X650S
To replace the SI40X650S, order the SAI40X650S, confirming the ISO 15552 interface, 40mm bore, 650mm stroke, G1/4 port (PT/G/NPT) and mounting accessory. The -S magnet equates to the SAI-S. For sizing both ways: a 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N. A plain cylinder drifts on air loss as the cushion only decelerates; for load holding use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. At 650mm stroke, prevent rod bending by guiding the load externally to avoid side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X650S
- ✓ 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 SI40X650S FAQ
Yes, the SI40X650S is discontinued. The direct replacement is the SAI40X650S. It is dimensionally interchangeable per ISO 15552, matching the 40mm bore, 650mm stroke, 628N force, G1/4 port and mounting interface.
The G1/4 port bore delivers 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, and a theoretical max of 128kgf at 1.0MPa. It operates at 30-800mm/s with a 27mm adjustable cushion.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X650S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X650S replacement — usually within 7-8 hours.