This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X450S, 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 SI40X450S
The AirTAC Airtac SI40 Standard Cylinder SI40X450S 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 SAI40X450S, 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 → SAI40X450S
- 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 SI40X450S
The AirTAC SI40X450S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 450 mm stroke. It delivers 628 N push force at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI40X450S, a direct replacement retaining the exact ISO 15552 mounting interface, bore, stroke, output force, and port size.
The SAI upgrade features a revised piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life. It also introduces SAIL, SAIF, and BSAI lock variants absent in the SI line. The original -S magnet supports CS1-B/DS1-B switches, while the SAI uses current AirTAC sensors.
Airtac SI40 Standard Cylinder SI40X450S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X450S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X450S |
| 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 SAI40X450S 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 SAI40X450S 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 SI40X450S
| 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 SI40X450S Is Used
Package Diverting
Drives diverter arms on sorting lines, using the 450 mm stroke to push parcels cleanly between adjacent conveyor belts without collision.
Vertical Lift Gates
Raises lightweight access gates or safety barriers.
Component Ejection
Ejects machined parts from fixtures. The 628 N push force at 0.5 MPa clears binding chips, while the 450 mm stroke clears the machining envelope.
Replacing the Airtac SI40 Standard Cylinder SI40X450S with the SAI40X450S
To replace the SI40X450S, order the SAI40X450S and confirm the ISO 15552 mounting interface, 40 mm bore, 450 mm stroke, G1/4 port (PT/G/NPT), and mounting accessory. The -S magnet transfers directly, though you should upgrade to current AirTAC switches since the legacy CS1-B/DS1-B set is obsolete. For sizing, the 32 mm bore yields 402 N push at 0.5 MPa, while the 50 mm bore yields 982 N; alternatively, pushing 0.7 MPa on the 40 mm yields 879 N. Because stroke is 450 mm, add external guides to prevent rod bending and side-load wear. A plain cylinder drifts without live air; for load holding, use an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X450S
- ✓ 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 SI40X450S FAQ
Yes, the SI40X450S is discontinued. The direct replacement is the SAI40X450S. It is dimensionally interchangeable per ISO 15552, matching the 40 mm bore, 450 mm stroke, G1/4 port, and mounting interface, so it fits existing fixtures directly.
The 40 mm bore uses a G1/4 port. At 0.5 MPa it provides 628 N push and 528 N pull. At 0.7 MPa push is 879 N, and at 0.9 MPa it is 1130 N. The theoretical maximum force is 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X450S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X450S replacement — usually within 7-8 hours.