David Billington wrote:
Unforetunately these are subjected to bending in use and I was aiming
to use EN24T (817M40) (4340?) which I have some of in 1/4" diameter.
Makes it a more challenging project.

Are you concerned about failure in bending due to exceeding the elastic
limit or non-destructive flexing? What is the stress level? As long as
the stress is well below the yield strength of the steel which alloy you
use doesn't matter. All steels have a modulus of elasticity of
approximately 30E6. If the max. bending stress in your object was (say)
10Kpsi, mild steel would bend the same amount as heat treated 4340 or
High Speed Steel or ...

Ted