Egyptian flint, Neolithic Period (5500 - 3100 BC). A hand axe or biface is a prehistorical stone tool with two faces, and the longest-used tool in human history. Its technical name (biface) comes from the fact that the archetypical model is a generally bifacial Lithic flake with an almond-shaped morphology. The most common hand axes have a pointed end and rounded base, which gives them their characteristic shape, and both faces have been knapped to remove the natural cortex, at least partially.