Why the Frame Rings of FX800 and Larger Butt Fusion Machines Are Finished in Black

FX800 and larger butt fusion machines are equipped with black-finished upper and lower frame rings rather than the standard blue commonly used on smaller models. This difference is not a design or branding choice, but a result of material properties and manufacturing processes.

Within the FX series, models starting from FX800 use a different material formulation for the frame rings. This formulation includes additional components required to meet the structural demands of large-diameter equipment. After high-temperature forging, the surface of these frame rings naturally exhibits certain visible imperfections. This surface condition is an objective outcome of the material selection and forging process.

If a blue paint finish were applied to these forged surfaces, the imperfections would become more visually pronounced, negatively affecting the overall appearance and perceived quality of the machine. To address this, a black finish is applied, which helps reduce the visual impact of these surface characteristics and provides a more uniform and stable appearance.

As a result, the black finish used on the frame rings of FX800 and larger models is not intended to alter the product’s visual identity. Instead, it is a practical solution that aligns the surface treatment with the actual forged condition of the material, ensuring a more balanced and consistent appearance that is appropriate for large-scale welding equipment.