This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X590S, 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 SI50X590S
The AirTAC Airtac SI50 Standard Cylinder SI50X590S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 590mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X590S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke590 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X590S
- 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 SI50X590S
The AirTAC SI50X590S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 590mm stroke. It delivers 982N push force at 0.5MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50X590S, a direct upgrade sharing the exact mounting interface, bore, stroke, force, and port size.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SAI family also adds lock and valve variants (SAIL, SAIF, BSAI) the SI lacked. Your -S suffix means a piston magnet for legacy CS1-B/DS1-B sensors; the SAI uses current AirTAC switches.
Airtac SI50 Standard Cylinder SI50X590S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X590S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X590S |
| Bore size | Ø50 mm |
| Stroke | 590 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 SAI50X590S 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 SAI50X590S 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 SI50X590S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×590 | 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 SI50X590S Is Used
Long-Stroke Diversion
Pushes packages across transfer lines using the 590mm stroke and 982N force, requiring external guides to prevent rod bending.
Parts Ejection
Ejects machined components from fixtures, relying on the adjustable 30mm air cushions to decelerate at stroke end.
Replacing the Airtac SI50 Standard Cylinder SI50X590S with the SAI50X590S
To replace your SI50X590S, order the SAI50X590S. Confirm the ISO 15552 mounting interface, G1/4 port, M16x1.5 rod thread, and your specific mounting accessory (LB, FA, TC, etc.). The -S magnet is retained. If you need less force, a 40mm bore provides 628N push at 0.5MPa; if you need more, a 63mm bore yields 1559N. Remember, a plain cylinder drifts on air loss—the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL lock variant. Because the 590mm stroke is long, use an external guide to prevent rod bending and side-load damage.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X590S
- ✓ 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 SI50X590S FAQ
Yes, the SI50X590S is discontinued. The direct replacement is the SAI50X590S. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 590mm stroke, 982N force, and G1/4 port.
The 50mm bore uses a G1/4 air port. Force ratings are 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical max of 200kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X590S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X590S replacement — usually within 7-8 hours.