This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X1550S, 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 SI50X1550S
The AirTAC SI50 Standard Cylinder SI50X1550S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 1550mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X1550S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke1550 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X1550S
- 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 SI50X1550S
The AirTAC SI50X1550S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 1550mm stroke. Generating 982N push force at 0.5MPa, this non-standard stroke length (exceeding the 1200mm maximum) was made-to-order. The direct replacement is the SAI50X1550S, retaining the same G1/4 port, M16x1.5 rod thread, and 30mm cushions.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family adds SAIL, SAIF, and BSAI lock variants the SI lacked. Your -S magnet works with legacy CS1-B/DS1-B sensors; the SAI uses current AirTAC switches.
Airtac SI50 Standard Cylinder SI50X1550S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X1550S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X1550S |
| Bore size | Ø50 mm |
| Stroke | 1550 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 SAI50X1550S 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 SAI50X1550S 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 SI50X1550S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×1550 | 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 SI50X1550S Is Used
Long-Stroke Diversion
Pushes packages across wide conveyor lanes using the full 1550mm travel, relying on external guides to prevent rod bending during the transfer.
High-Bay Extraction
Extracts totes from deep shelving racks where the 982N push force at 0.5MPa handles loaded containers up to the 50kg vertical lift limit.
Material Ejection
Ejects machined parts from automated cells, using the adjustable 30mm cushions to decelerate the payload smoothly at full extension.
Replacing the Airtac SI50 Standard Cylinder SI50X1550S with the SAI50X1550S
To replace the SI50X1550S, order the SAI50X1550S. Confirm the ISO 15552 mounting interface, 50mm bore, 1550mm stroke, G1/4 port, and your mounting accessory. Because 1550mm exceeds the 1200mm standard stroke, this is a non-standard made-to-order item. At 0.5MPa it yields 982N push and 825N pull; if undersizing, a 40mm bore gives 628N. For 1550mm strokes, external guides are critical to prevent rod bending and side-load damage. The cushion only decelerates; it does not hold load on air loss, so use an external rod lock or pilot check valve for holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X1550S
- ✓ 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 SI50X1550S FAQ
Yes, the SI50X1550S is discontinued. The direct replacement is the SAI50X1550S. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 1550mm stroke, G1/4 port, and mounting interface.
The 50mm bore features a G1/4 port. It delivers 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, and a theoretical maximum of 200kgf at 1.0MPa. Operating speed is 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X1550S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X1550S replacement — usually within 7-8 hours.