This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X450STC, 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 SI40X450STC
The AirTAC Airtac SI40 Standard Cylinder SI40X450STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 450mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X450STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke450 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X450STC
- 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 SI40X450STC
The AirTAC SI40X450STC is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 450mm stroke. It delivers 628N push and 528N pull at 0.5MPa via a G1/4 port. AirTAC replaced this unit with the SAI40X450STC, a direct sharing the same TC trunnion mount, M12x1.25 rod thread, and dimensions. The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life.
The SAI family adds SAIL, SAIF, and BSAI lock variants missing from the SI line. This -S model has a piston magnet for legacy CS1-B/DS1-B sensors; the SAI uses current AirTAC switches. A 450mm stroke requires external guides to prevent rod bending.
Airtac SI40 Standard Cylinder SI40X450STC Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X450STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X450STC |
| Bore size | Ø40 mm |
| Stroke | 450 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 SAI40X450STC 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 SAI40X450STC 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 SI40X450STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×450 | 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 SI40X450STC Is Used
Material Diverting
Drives sorting gates on packaging lines using the TC trunnion mount to handle pivot arcs across the 450mm stroke.
Pneumatic Ejection
Pushes rejected parts off a conveyor belt, utilizing the 628N thrust and adjustable 27mm end cushions.
Replacing the Airtac SI40 Standard Cylinder SI40X450STC with the SAI40X450STC
To replace the SI40X450STC, order the SAI40X450STC. Confirm the ISO 15552 TC trunnion interface, 40mm bore, 450mm stroke, G1/4 port (PT/G/NPT), and the -S magnet. The SAI drops directly into existing fixtures. For sizing alternatives, a 32mm bore gives 402N push at 0.5MPa, while a 50mm bore yields 982N. At 450mm, add external guides to prevent side-load and rod-bending. The air cushion only decelerates; it does not hold load. For dead-load holding, use an external rod lock, a pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X450STC
- ✓ 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 SI40X450STC FAQ
Yes, the SI40X450STC is discontinued. The direct replacement is the SAI40X450STC. It shares the identical ISO 15552 mounting interface, 40mm bore, 450mm stroke, G1/4 port, and output force, fitting existing fixtures perfectly.
The 40mm bore uses a G1/4 port. It provides 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical maximum of 128kgf at 1.0MPa. Operating speed is 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X450STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X450STC replacement — usually within 7-8 hours.