This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X445S, 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 SI50 Standard Cylinder SI50X445S
The AirTAC Airtac SI50 Standard Cylinder SI50X445S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 445mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X445S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke445 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X445S
- 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 SI50 Standard Cylinder SI50X445S
The AirTAC SI50X445S is a discontinued double-acting ISO 15552 profile cylinder featuring a 50mm bore, 445mm stroke, and a built-in piston magnet for CS1-B/DS1-B switches. Delivering 982 N push and 825 N pull at 0.5 MPa, it is replaced by the SAI50X445S. This direct upgrade shares the exact G1/4 port, M16x1.5 rod thread, and ISO 15552 mounting interface, fitting existing fixtures perfectly.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life, while adding SAIL, SAIF, and BSAI lock variants the SI lacked. For this 445mm stroke, use external guides to prevent rod bending. Note that plain cylinders drift without air; use an external rod lock or pilot check valve for load holding.
Airtac SI50 Standard Cylinder SI50X445S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X445S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X445S |
| Bore size | Ø50 mm |
| Stroke | 445 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| Rod thread | M16×1.5 |
| 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, 30 mm |
| Max standard stroke | Up to 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI50X445S carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø50mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 982 N | 825 N |
| 0.7 MPa | 1374 N | — |
| Max (@1.0 MPa) | 200 kgf | |
The SAI50X445S produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI50 Standard Cylinder SI50X445S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×445 | 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 SI50 Standard Cylinder SI50X445S Is Used
Material Diversion
Actuates routing gates on packaging lines, utilizing the 982 N push force to redirect heavy cartons reliably at speed.
Pallet Handling
Pushes pallets or totes into staging zones, benefiting from the adjustable 30mm air cushions to halt travel smoothly.
Replacing the Airtac SI50 Standard Cylinder SI50X445S with the SAI50X445S
To replace the SI50X445S, order the SAI50X445S, confirming the ISO 15552 interface, 50mm bore, 445mm stroke, G1/4 port (PT/G/NPT), and the -S magnet for current AirTAC switches. Sizing both ways: a 40mm bore yields 628 N push at 0.5 MPa, while a 63mm bore yields 1559 N. At 445mm, add external guides to prevent side-load and rod-bending. The air cushion only decelerates; it does not hold. For load holding on air loss, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X445S
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI50 Standard Cylinder SI50X445S FAQ
Yes, the SI50X445S is discontinued. The direct replacement is the AirTAC SAI50X445S. It shares the identical ISO 15552 mounting interface, 50mm bore, 445mm stroke, output force, and G1/4 port, fitting existing fixtures without modification.
The 50mm bore uses a G1/4 air port and an M16x1.5 rod thread. Force output is 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and 1767 N push at 0.9 MPa. The theoretical maximum force is 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X445S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X445S replacement — usually within 7-8 hours.