This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX650S, 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 SI40AX650S
The AirTAC SI40 Standard Cylinder SI40AX650S 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 SAI40AX650S, 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 → SAI40AX650S
- 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 SI40AX650S
The AirTAC SI40AX650S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 650mm stroke. Delivering 628N push force at 0.5MPa, it features a SUS420J2 stainless rod, G1/4 port, and a piston magnet for CS1-B/DS1-B sensors. AirTAC replaced this with the SAI40AX650S.
The SAI40AX650S is a direct replacement retaining the exact ISO 15552 mounting interface, M12x1.25 thread, and 128kgf max force. It upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure.
Airtac SI40 Standard Cylinder SI40AX650S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX650S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX650S |
| 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 SAI40AX650S 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 SAI40AX650S 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 SI40AX650S
| 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 SI40AX650S Is Used
Long-Stroke Diverting
Pushes packages across transfer lines with a 650mm reach, utilizing the 628N force at 0.5MPa while requiring external guides to prevent rod bending.
Stainless Rod Ejection
Ejects parts in humid washdown environments using the SUS420J2 stainless piston rod, relying on the 30-800mm/s speed range for rapid cycling.
Replacing the Airtac SI40 Standard Cylinder SI40AX650S with the SAI40AX650S
To replace the SI40AX650S, order the SAI40AX650S and confirm the ISO 15552 mounting interface, 40mm bore, 650mm stroke, G1/4 port, and -S magnet for current AirTAC switches. The -A code specifies a SUS420J2 stainless rod; if corrosion is not a concern, the default carbon steel rod works. At 0.5MPa it pushes 628N; sizing up to a 50mm bore yields 982N. Because the 650mm stroke risks rod bending under side loads, use external guides to prevent premature seal wear. The cushion only decelerates the load; for holding position on air loss, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX650S
- ✓ 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 SI40AX650S FAQ
Yes, the AirTAC SI40AX650S is discontinued. The direct replacement is the SAI40AX650S. It shares the identical ISO 15552 mounting interface, 40mm bore, 650mm stroke, G1/4 port, and 128kgf max force, but features an upgraded two Y-shaped piston seal for lower start-up pressure.
The G1/4 port bore delivers a push force of 628N and a pull force of 528N at 0.5MPa. At 0.7MPa it pushes 879N, and 1130N at 0.9MPa. The theoretical maximum force is 128kgf at 1.0MPa, operating at 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40AX650S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX650S replacement — usually within 7-8 hours.