Originally Posted by
pierce
the auto industry liked to call aluminum alloy wheels "mags" because many of them contained some small percentage of magnesium, but in fact virtually all of them are mostly aluminum.
To further complicate things, british convention is to call the damn things "alloys", as in "watch out, you're gonna kerb the alloys!"
but more often they say alloy (ally nipples, alloy steerer, alloy seatpost) mostly to generally distinguish from either brass (nipples) or carbon.
Slightly ironically, brass nipples could be referred to as "alloy" as well, brass being an alloy.