This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X550TC, 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 SI40X550TC
The AirTAC Airtac SI40 Standard Cylinder SI40X550TC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 550mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X550TC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke550 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X550TC
- 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 SI40X550TC
The AirTAC SI40X550TC is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 550mm stroke. Delivering 628N push force at 0.5MPa via a G1/4 port, it is replaced by the SAI40X550TC. This direct successor shares the exact ISO 15552 mounting interface, TC trunnion, and M12x1.25 rod thread.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life. Without a magnet (-S), this specific SKU cannot accept a sensor. The family adds SAIL, SAIF, and BSAI lock variants the SI lacked.
Airtac SI40 Standard Cylinder SI40X550TC Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X550TC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X550TC |
| Bore size | Ø40 mm |
| Stroke | 550 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 SAI40X550TC 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 SAI40X550TC 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 SI40X550TC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×550 | 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 SI40X550TC Is Used
Material Diversion
Drives routing gates on transfer lines using the TC trunnion to handle the 628N push load over the 550mm travel.
Pallet Push-Off
Ejects light pallets from accumulation zones, requiring external guides to manage side-load over the long stroke.
Replacing the Airtac SI40 Standard Cylinder SI40X550TC with the SAI40X550TC
To replace this SI40X550TC, order the SAI40X550TC. Confirm the ISO 15552 TC trunnion mount, 40mm bore, 550mm stroke, G1/4 port, and M12x1.25 thread. Because this SKU lacks a magnet, it cannot take a CS1-B/DS1-B sensor; order an SAI with -S if sensing is needed. At 550mm, use external guides to prevent rod bending and side-load wear. To size up or down, neighbor bores (32mm or 50mm) offer 402N or 982N push at 0.5MPa. A plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external pilot check valve, rod lock, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X550TC
- ✓ 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 SI40X550TC FAQ
Yes, the SI40X550TC is discontinued. The direct replacement is the SAI40X550TC. It is a true ISO 15552 profile cylinder with the same 40mm bore, 550mm stroke, 628N force, G1/4 port, and TC mounting interface, fitting existing fixtures perfectly.
The bore is 40mm with a G1/4 air port. At 0.5MPa it provides 628N push and 528N pull force. At 0.7MPa push is 879N, and 1130N at 0.9MPa. The theoretical maximum force is 128kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X550TC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X550TC replacement — usually within 7-8 hours.