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
PLANE FOR KID
In another child's room you can see the ugly picture all corners littered with toys. Why are there only, especially if the child is a boy. All kinds of machines — from small to huge,...
START FROM UNDER THE WATER
Japanese seaplane E14Y. The first production Е9W1 hydroplanes equipped with boats I-7 and I-8, after which in 1937 the serial production of these aircraft continued. Just released 32...
