On 5 Apr, 07:40, (Ross Hebeisen) wrote:

seems to me they are made like a barrel is made with steel bands
around them. sound right?

Nope. They're always (*) made from solid. They're often banded too,
but they're not stave-built like a barrel.

* Some huge hubs are made from pieces, owing to their sheer size. This
is millwright's work, not wheelwright's. I'm talking about the hubs
for horse gins, mill wheels, windmill gears or trip hammers, rather
than even big cartwheels. The joinery on these things is as complex as
Japanese temple carpentry work. As they're big sections, then oak is
more common than elm. Oak in bulk is stronger than elm, elm's virtue
is in that rippled grain retaining its strength down to thin sections.