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
Recommend to read
AIR FERRY
Once in the journal "modelist-Konstruktor" I read the article "the Farmer's sloping field." The air route is very much needed in the highlands. But in nature, there are many horizontal...
WINGED JEEP
The passenger plane the Yak-12. For many worldwide known aircraft designers and their teams, the road to big aviation began with the creation of a light aircraft. Often, these are the...
