This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX300S, 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 SI50BX300S
The AirTAC Airtac SI50 Standard Cylinder SI50BX300S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 300mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX300S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke300 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX300S
- 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 SI50BX300S
The AirTAC SI50BX300S is a discontinued double-acting ISO 15552 profile cylinder featuring a 50mm bore, 300mm stroke, and a SUS304 stainless steel rod. Delivering 982 N push force at 0.5 MPa, it is replaced by the SAI50BX300S. This direct successor shares the exact G1/4 port, M16x1.5 thread, and mounting interface.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The original -S magnet works with legacy CS1-B/DS1-B sensors, while the SAI accepts current AirTAC switches.
Airtac SI50 Standard Cylinder SI50BX300S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX300S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX300S |
| Bore size | Ø50 mm |
| Stroke | 300 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 SAI50BX300S 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 SAI50BX300S 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 SI50BX300S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×300 | 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 SI50BX300S Is Used
Stainless Rod Diverter
Ideal for pushing packages on a washdown conveyor line, utilizing the 300mm stroke and SUS304 rod for corrosion resistance.
External Guided Press
Performs light-duty pressing operations where external guides prevent rod bending during the 300mm travel.
Replacing the Airtac SI50 Standard Cylinder SI50BX300S with the SAI50BX300S
To replace this SI50BX300S, order the SAI50BX300S, confirming the ISO 15552 mounting interface, 50mm bore, 300mm stroke, G1/4 port, and SUS304 rod. If you need less force, the 40mm bore offers 628 N push at 0.5 MPa; for more power, the 63mm 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 specify the SAIL/BSAI lock variant. At 300mm stroke, prevent rod bending by using external guides to absorb side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX300S
- ✓ 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 SI50BX300S FAQ
Yes, the SI50BX300S is discontinued. The direct replacement is the SAI50BX300S. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 300mm stroke, force, G1/4 port, and mounting fixtures.
It features a G1/4 air port. The force ratings are: 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; with a theoretical maximum of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX300S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX300S replacement — usually within 7-8 hours.