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
SCHOOL INNOVATION: FROM IDEA TO REALITY
Creative finds of young technicians, the successful resolution of their original design objectives our magazine told repeatedly. Examples of research innovation activities of school...
“THE JANITOR” — ON THE WINDOW
Replacing outdated car "janitor", as often called the wiper, attach the handle with extension rod — get a handy household tool for cleaning home Windows.
