Good defense crook cane

Hickory and Ash both make good axe handles and also make good canes that don't break.
I got a good Ash cane at Tractor supply. They are made for herding cattle in feed lots. So they are plenty long.
I have swung these canes at a heavy bag without breaking. So you might look into these. DR

Sorry I did not see this earlier, But Straight grain Hickory seems to hold up best. I have a 1" hickory cane that I have been wailing on the heavy bag for a couple years now without any damage. The trick is to keep it oiled and the moisture sealed in. When it gets beat up I recoat it with Boiled Linseed Oil.
I also have an ash bent cane that has held up to anything I have done to it. [ But I have not used it in workouts].
Here's a good site for SD canes and sticks.

Self-Defense Canes | Self Defense Walking Cane | Cane Masters
DR