This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X590STC, 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 SI50X590STC
The AirTAC Airtac SI50 Standard Cylinder SI50X590STC 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 SAI50X590STC, 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 → SAI50X590STC
- 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 SI50X590STC
The AirTAC SI50X590STC 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 unit with the SAI50X590STC, a direct replacement retaining the exact interface, stroke, force, and TC trunnion mount.
The SAI upgrade features a refined piston seal using two Y-shaped one-way elements for low start-up pressure and extended life. This -S model includes a magnet for legacy CS1-B/DS1-B sensors, and the SAI family adds lock variants like SAIL and BSAI absent in the SI line.
Airtac SI50 Standard Cylinder SI50X590STC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X590STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X590STC |
| 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 SAI50X590STC 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 SAI50X590STC 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 SI50X590STC
| 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 SI50X590STC Is Used
Long-Stroke Diversion
Drives large packages across a 590mm span on packaging lines where the 982N push force easily overcomes carton friction.
Vertical Material Lowering
Lowers 50kg fixtures smoothly using the adjustable 30mm cushions, requiring an external check valve to hold the load safely.
Pallet Handling Gate
Actuates heavy safety gates on palletizer enclosures, utilizing the TC trunnion mount to accommodate the long-rod pivot.
Replacing the Airtac SI50 Standard Cylinder SI50X590STC with the SAI50X590STC
To replace the SI50X590STC, order the SAI50X590STC. Confirm the ISO 15552 mounting interface, 50mm bore, 590mm stroke, G1/4 port (PT/G/NPT thread options), TC trunnion mount, and the -S magnet. If you need more force, the neighboring 63mm bore yields 1559N at 0.5MPa; if less is acceptable, the 40mm bore yields 628N. Because this is a 590mm stroke, use an external guide to prevent rod bending and side-load damage. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X590STC
- ✓ 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 SI50X590STC FAQ
Yes, the SI50X590STC is discontinued. The direct replacement is the SAI50X590STC. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 590mm stroke, 982N force, G1/4 port, and TC mounting interface.
The 50mm bore uses a G1/4 air port. At 0.5MPa it provides 982N push and 825N pull force. At 0.7MPa push is 1374N, and at 0.9MPa it is 1767N. The theoretical maximum force is 200kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X590STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X590STC replacement — usually within 7-8 hours.