hub details

[Bukowski]

the hub (well, mine anyways - and the brake rotor surface that it mates to) have a concentric circular groove pattern, on the mating faces. so if you scrape your fingernail towards the edge, it will grab the ridges. the ridges are slight.

is there a functional significance to this pattern? I imagine it could be important to avoid flat pieces of aluminum hub and steel rotor welding together under heat. then there's the brake grease which should keep them healthy.

reason I ask - taking the corrosion off is requiring some more detailed brass-brushing/sanding. hope to post pics soon.

related to another thread of mine: basics : removing brake rotors

[Techno Duck]

Those are just machining marks.