This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X550, 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 SI50X550
The AirTAC Airtac SI50 Standard Cylinder SI50X550 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 550mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X550, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke550 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X550
- 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 SI50X550
The AirTAC SI50X550 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 550mm stroke, delivering 982N push force at 0.5MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50X550, a direct upgrade retaining the exact interface, dimensions, and output.
The SAI50X550 features an upgraded piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life. Note this non-magnet SKU cannot accept a sensor, and the 550mm stroke requires external guides to prevent rod bending.
Airtac SI50 Standard Cylinder SI50X550 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X550 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X550 |
| Bore size | Ø50 mm |
| Stroke | 550 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 SAI50X550 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 SAI50X550 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 SI50X550
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×550 | 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 SI50X550 Is Used
Carton Diverting
Pushes packages at 30-800 mm/s along sorting lines where the 982N thrust easily redirects standard pallet loads.
Material Lowering
Regulates the descent of workpieces using adjustable air cushions, though an external check valve is needed to hold loads.
Long-Reach Transfer
Handles 550mm extraction tasks in storage racks, requiring external guides to prevent rod bending over the extended length.
Replacing the Airtac SI50 Standard Cylinder SI50X550 with the SAI50X550
To replace the SI50X550, order the SAI50X550, confirming the ISO 15552 mounting interface, 50mm bore, 550mm stroke, G1/4 port, and M16x1.5 rod thread. Because this 550mm stroke exceeds 300mm, add external guides to prevent rod bending and side-load wear. Sizing options: step down to a 40mm bore for lighter loads, or up to a 63mm bore (1402N pull at 0.5MPa) for heavier force. This plain cylinder lacks a magnet, so it cannot take CS1-B/DS1-B sensors; for position feedback, select an SAI50X550S. For load holding on air loss, the cushion only decelerates; use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X550
- ✓ 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 SI50X550 FAQ
Yes, the SI50X550 is discontinued. The direct replacement is the SAI50X550, which shares identical ISO 15552 mounting dimensions, 50mm bore, 550mm stroke, and G1/4 port.
The G1/4 port cylinder delivers 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, and a maximum theoretical force of 200kgf at 1.0MPa.
Request a Quote for the SAI50X550
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X550 replacement — usually within 7-8 hours.