What is the minimum m of an object in space before gravity naturally shapes the object into a sphere?

It involved the spin of the object and its material state to a large degree. Certainly, a molten liquid planet wouldn't tend to have mountian ranges and canyons. The spin distorts the natural shape to more ovaloid from spheroid. Asteroids (et al) are composed of solid matter (ice and rock, for instance). It is less influenced than our planets, which had a molten or gaseous past (and some also present)