Stone axe and destroying things

[SamaR]

Wiki about Stone Axe: "It increases the effectiveness of chipping stone and destroying objects. "how to calculate how much damage they give when destroying things like Sledgehammer adds four,Pickaxe 2

[Procne]

I think it doesn't add any bonus damage.
So final damage will be standard sqrt(strength)-soak

[Potjeh]

Stone axe adds 1.