The drilling of metals requires precision, delicacy and a certain strength.
We distinguish the metals according to their hardness.
Are considered hard alloys to drill cast iron and hard steels.
Next are medium hard steels and mild steels, which are more common.
Bronzes, brass, aluminum, tin and zinc are considered as soft metals.
The harder the metal to drill, the lower the drilling speed.
For mild steels and soft metals use a laminated drill bit.
For hard and medium hard steels, use a HSS high speed steel ground drill bit.
The titanium nitride drill is designed for very high efficiency.
The drilling of the metal is always in rotation and without percussion.
The use of a bench drill press is often essential for the metal. It guarantees the accuracy of the work to be done. Simply lower the chuck / drill block to the mark with one hand.
The laser beam centering device that equips some machines is very practical when it is necessary to drill cylindrical parts repeatedly or with great precision.
As you have a free hand, it is easy to lubricate the drill with cutting oil when drilling hard metals. This avoids the heating of the drill. Remember to adjust the speed.
The soft metals are pierced on a support to avoid any deformation (here, brass threshold bar).
Using a punch, slightly mark the future hole: it will prevent the drill from skidding.
Drilling large diameters in aluminum or other soft metal requires the use of a hole saw specifically adapted to metals. Again, consider lubricating and adjusting the speed.