This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X390, 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 SI50X390
The AirTAC Airtac SI50 Standard Cylinder SI50X390 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 390mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X390, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke390 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X390
- 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 SI50X390
The AirTAC SI50X390 is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 390 mm stroke. It delivers 982 N push force at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50X390, a direct sharing the exact ISO 15552 mounting interface, bore, 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. For this non-magnet SKU, a position switch cannot be fitted. The SAI family also introduces SAIL, SAIF, and BSAI lock variants absent from the SI line.
Airtac SI50 Standard Cylinder SI50X390 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X390 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X390 |
| Bore size | Ø50 mm |
| Stroke | 390 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 SAI50X390 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 SAI50X390 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 SI50X390
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×390 | 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 SI50X390 Is Used
Package Diverting
Drives diverting arms on packaging lines, utilizing the 390 mm stroke to route standard totes at a safe 589 N working load.
Gate Operation
Actuates material handling gates, providing 982 N of push force at 0.5 MPa to move mechanical barriers reliably.
Replacing the Airtac SI50 Standard Cylinder SI50X390 with the SAI50X390
To replace the SI50X390, order the SAI50X390, confirming the ISO 15552 mounting interface, 50 mm bore, 390 mm stroke, G1/4 port (PT/G/NPT), and mounting accessory. This SKU lacks the -S magnet, so it cannot accept a CS1-B or DS1-B sensor; choose an SAI model with the magnet if position detection is needed. Sizing both ways: a 40 mm bore yields 628 N push at 0.5 MPa, while a 63 mm bore yields 1559 N. Because this is a 390 mm stroke, use external guides to prevent rod bending and side-load damage. A plain cylinder drifts on air loss; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X390
- ✓ 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 SI50X390 FAQ
Yes, the AirTAC SI50X390 is discontinued. The direct replacement is the SAI50X390. It shares the identical ISO 15552 mounting interface, 50 mm bore, 390 mm stroke, force, and G1/4 port, fitting existing fixtures perfectly.
The 50 mm bore uses a G1/4 air port. 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.
Request a Quote for the SAI50X390
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X390 replacement — usually within 7-8 hours.