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Wheel nut bearing surface.

A mechanic kept saying that tapered nuts were good for wheel nuts in endurance for 12 hours. There are normal nut types and bolt types for wheel nuts, but here I would like to write what I think about the seat surface, that is, the connection surface with the wheel.

There are roughly three types of seating surfaces. Tapered type with a mortar-shaped tip that narrows linearly. Spherical seat type that is literally spherical. The ground contact surface is a flat seat type.