Very often, a broken drill should just throw it away because of the inability to even re-ground it. However, it can be converted into a punch. It is enough to the breaking point to make the angle marked in the figure. For such an operation better suited for the drill of large diameter. This punch will make it easier to obtain holes in concrete. Slightly after each hammer blow, the punch should be slightly rotated around the axis.
L. ANDARALO, M and n s K, Belarus