This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X650, 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 SI40X650
The AirTAC Airtac SI40 Standard Cylinder SI40X650 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 SAI40X650, 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 → SAI40X650
- 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 SI40X650
The AirTAC SI40X650 is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 650 mm stroke. It delivers 628 N push and 528 N pull at 0.5 MPa, utilizing a G1/4 port and a 16 mm carbon steel rod. AirTAC replaced this legacy unit with the SAI40X650, a direct replacement retaining the exact ISO 15552 mounting interface, stroke, output force, and port size.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note that this specific SKU lacks a magnet (-S), meaning it cannot accept position sensors; the legacy SI family used CS1-B/DS1-B switches, while the SAI family uses current AirTAC sensors. Furthermore, the SAI line introduces SAIL, SAIF, and BSAI lock variants absent in the original SI series.
Airtac SI40 Standard Cylinder SI40X650 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X650 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X650 |
| 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 SAI40X650 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 SAI40X650 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 SI40X650
| 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 SI40X650 Is Used
Material Diversion
Drives sorting flaps on packaging lines, utilizing the 628 N push force to redirect cartons at high speeds.
Vertical Lowering
Lowers light fixtures safely, handling the 32 kg vertical lift capacity with controlled air cushioning.
Pallet Handling
Actuates 650 mm stroke pushers to index pallets along accumulation zones without external hydraulics.
Replacing the Airtac SI40 Standard Cylinder SI40X650 with the SAI40X650
To replace the discontinued SI40X650, order the SAI40X650. Verify your existing fixture's ISO 15552 mounting interface (LB, FA, CA, TC, etc.), the 650 mm stroke, and the G1/4 port (available in PT, G, or NPT). Because this SKU lacks the -S magnet, it cannot support sensing; if position detection is required, select an SAI40X650S and pair it with current AirTAC switches. When sizing, consider neighboring bores: a 32 mm bore offers 402 N push @0.5 MPa, while a 50 mm bore provides 982 N. A plain cylinder will not hold a load without live air—the cushion only decelerates—so for load-holding, use an external pilot check valve or explore the SAIL/BSAI lock variants. Finally, at 650 mm, the 16 mm rod is susceptible to bending; ensure external guides prevent side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X650
- ✓ 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 SI40X650 FAQ
Yes, the SI40X650 is discontinued. The direct replacement is the AirTAC SAI40X650. It is dimensionally interchangeable per ISO 15552, matching the 40 mm bore, 650 mm stroke, G1/4 port, and mounting interface, so it fits existing fixtures perfectly.
The 40 mm bore features a G1/4 air port and a 16 mm rod. It generates 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 of 128 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Request a Quote for the SAI40X650
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X650 replacement — usually within 7-8 hours.