Charlie Self schreef
Wish I could find a Janka chart that included red gum: it is a bit hard to
find, but you'd think that somewhere, some time someone would have wanted
to use it for flooring, so a flooring manufacturer would have tested it.

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Actually it is in all the books
The figure given is 3780.80 N (850 lbf)
A bit harder than silver maple, almost exactly as hard as bigleaf maple