A wheel is a fitting emblem for friendship between women-- friends positioned in a circle, facing each other, and considering a common interest. More often than not, this common interest will be an infant or child.  If the subject is an idea rather than a person, it will likely be the relations between people that result in children.

By contrast, the emblem for manly friendship is a ladder-- companions facing in the same direction, connected by the effort of accomplishing a common goal.

From childhood, boys will build their friendships in this way.  Team sports can be an important means. But approaching manhood, young men need to learn friendship in work, particularly physical work which involves shared hardships and the exhilaration of regular tangible accomplishments.