Fluid duct with improved connecting bead

A fluid duct comprising:

• a plastic body having a forward cylindrical portion having an outer periphery, and a rear cylindrical portion having an outer periphery, said forward and rear cylindrical portions being at an equal radial distance from a center line of said fluid duct;
• a bead formed on an outer periphery of said duct body intermediate said forward and rear cylindrical portions, and said bead having a radially outermost distance measured perpendicularly away from said outer periphery of said forward cylindrical portion and defined as a first distance, and a second distance defined between a forward end of said duct body to a rearmost end of said bead, and a ratio of said first distance to said second distance being between 0.200 and 0.270;
• and
• a forward face of said bead is formed extending away from said forward cylindrical portion, and at a first radius of curvature, and a rear face of said bead merges into said rear cylindrical portion, with a second radius of curvature defined at a location where said bead merges into said rear cylindrical portion, and a ratio of said first radius of curvature to said second radius of curvature is between 2.1 and 4.8.