Do it yourself.
Although I don’t suggest burying an ax head next to your Oak shoots next spring. I highly recommend growing axes as a hobby. A man found an entire Axe. A root apparently found it first (Kansas man discovers a peculiar ax with a root for a handle in his front yard: NPR). I got smarted (Worm’s Use of Copper Could Point to Novel Material Designs – Scientific American).
Someone should be able to utilize the potential for trees to consume objects. In a controlled way someone should be grow an Axe with Handle and intentionally. The technique stressing on a tree limb or trunk can be taken advantage of. No manipulation of a trunk would be necessary to mount a sapling through the eye of the axe. The trunk growth will provide the pressure required to secure the axe. (What are the Parts of an Axe? axeandanswered.com).
It will be possible to bind or scar the trunk at the perfect length to provide a knob. In general, growers can adjust a saplings trunk during its maturation to fashion handle. Eventually we can experiment with supplementing to increase strength or appeal or both. Other material can run through the eye along the body and into the throat for interesting grips. Plus, multiple saplings will increase production while intertwining them could bring tensile relief. Are there other applications? I say, Plenty.