This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX650S, 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 SI50BX650S
The AirTAC Airtac SI50 Standard Cylinder SI50BX650S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 650mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX650S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke650 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX650S
- 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 SI50BX650S
The AirTAC SI50BX650S is a discontinued double-acting ISO 15552 profile cylinder featuring a SUS304 stainless piston rod and a 650 mm stroke. It delivers 982 N push force at 0.5 MPa through a G1/4 port. AirTAC replaced this with the SAI50BX650S, a direct upgrade retaining the exact ISO 15552 mounting interface, bore, stroke, 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. This -S model includes a piston magnet for legacy CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50BX650S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX650S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX650S |
| Bore size | Ø50 mm |
| Stroke | 650 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 SAI50BX650S 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 SAI50BX650S 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 SI50BX650S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×650 | 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 SI50BX650S Is Used
Vertical Material Lift
Lowers and raises loads up to 50 kg using the 650 mm stroke, relying on external guides to prevent rod bending during vertical transit.
Long-Stroke Diversion
Actuates diverter arms or gates along packaging lines where the 982 N push force easily overcomes friction over the extended travel distance.
Corrosive Environment Actuation
Utilizes the SUS304 stainless steel rod for washdown or chemical exposure areas, driving test fixtures with reliable double-acting power.
Replacing the Airtac SI50 Standard Cylinder SI50BX650S with the SAI50BX650S
To replace the SI50BX650S, order the SAI50BX650S. Confirm the ISO 15552 mounting interface, bore, 650 mm stroke, G1/4 port (PT/G/NPT thread), and mounting accessory. The -B rod is SUS304 stainless steel, and the -S denotes a magnet for CS1-B/DS1-B switches. At 650 mm, prevent rod bending by using external guides to manage side loads. For sizing, a 50 mm bore yields 982 N push at 0.5 MPa; dropping to a 40 mm bore gives 628 N, while a 63 mm bore provides 1559 N. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock or pilot check valve for load holding, or explore SAIL and BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX650S
- ✓ 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 SI50BX650S FAQ
Yes, the SI50BX650S is discontinued. The direct replacement is the SAI50BX650S. It shares the same ISO 15552 mounting interface, 50 mm bore, 650 mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly while adding an upgraded piston seal.
This 50 mm bore cylinder uses a G1/4 air port. It generates 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, 1767 N push at 0.9 MPa, and a theoretical maximum of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX650S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX650S replacement — usually within 7-8 hours.