[WalterBright]

> Why wouldn't you finish cutting through to make a slot?

Because then using the axe would quickly force the stone through the handle, as the only restraining force will be grip from the sides. That force on the sides will also encourage the handle to split. With it in a cup, the force will be on the back.

[nunuvit]

I'm skeptical that plant glue alone would work without additional lashing. Its brittleness is used as an intentional feature in hunting weapons so that the small blades detach and stay lodged in the prey.

[kragen]

i explained upthread how the celt design solves the splitting problem, which you have correctly identified