design of deep holes
Avoid interrupted cuts. Because the tungsten carbide head is fairly brittle, a gun drill should always cut into solid material to avoid breaking of the cutting edge. […]
effects of drill wandering
When drilling two deep holes from opposing sides to create an extra long hole, they may meet only partially. To prevent a flow restriction, the hole depths should be specified so that the holes overlap at least 10 mm at the meeting point. […]
cooling of cutting edge
The drill has a hole along it’s entire length through which coolant is pumped at high pressure. the coolant exits right behind the cutting edge. It cools and lubricates the drill for minimum friction within hole. It also washes the chip out through the open sector of the drill. The chips are then separated from [...]