On 18 June, 19:22, Vet Tech wrote:
I have a length of 10mm diam aluminium bar that I'd like to bend into
a hook shape.

Bend it cold, but use heat to anneal it if it's work hardened.

If it's already stiff (i.e. work hardened) then anneal it first.
Otherwise bend it _until_ it feels stiff, then anneal it. Don't
anneal it at the end, leave it hard.

To anneal it, wipe it with liquid soap and cook it with a gas torch
until the soap blackens. Then air cool or water quench, your call. It
won't crack.