Whether for small domestic tasks or precision engineering projects, metal drilling is certainly one of the most frequent manual tasks among amateurs and professionals.
Although the process is fairly simple and relatively little equipment is required, in order to achieve optimal drilling results, it is good to know the differences between various drill bits and the properties of the raw material to be drilled.
In this article we will look in detail at the definition of drilling, the tools to be used to achieve a good result, and the various types of drill bits for drilling into metal.
What is Metal Drilling?
Metal drilling allows the removal of material and the creation of holes in the surface using rotating and traversing machinery moving in an axial direction.
Depending on the machining method, the material and the tool used, various types of holes can be obtained. Some drill bits allow for minimal openings, with a diameter of a few millimetres, while others allow for drilling of several centimetres.
One material property that determines drilling work is the metal's machinability: that tendency to crumble when it is drilled or machined by removal. Machinability also determines the hardness of the metal - the harder a material is, the more difficult it will be to remove material.
Metal Drilling Tools
Whether stainless steel, aluminium or titanium, in order to achieve a good drilling job it is advisable to have a suitable tool kit, more or less professional depending on one's experience.
During the process it is possible for the material to generate sparks or debris, which is why it is advisable to use covering clothes and a protective mask. For safety reasons, if the surface to be worked on is small or movable, it is advisable to hold it in place with a vice or clamps.
An essential tool for drilling metal is the drill, but often a drilling machine can also be used. These machines allow flexible working thanks to their swivelling spindles and can only work by moving along the axis of the spindle itself. There are various types of drills on the market, ranging from impact drills to drill presses. If you are unfamiliar with these tools, it is a good idea to opt for handy and lightweight models.
Metal Drill Bits
In a precise and well-done DIY job, the choice of drill bit can be decisive.
The equipment becomes almost accessory if the drill bits used are not of good quality. Let's see how to recognise the various types of drill bits for drilling metal:
- Tungsten carbide drill bits: fitted with two cutting edges and a helix shape, they are suitable for machining various metals and drill small diameter holes;
- Insert drills: have a body and one or more inserts where the cutting edge is located. They can be used for even large diameter holes;
- Cusp drills: these are suitable for machining steel and cast iron and allow a high level of precision;
- Cannon drills: these are very long and perfect for deep drilling.
The choice of drill bit material also depends on the properties of the metal to be drilled. Super high-speed steel (HSS) and titanium nitride (TiN) coated drills are suitable for machining the most common metals.
Cobalt steel drills, on the other hand, are needed for drilling into stronger metals.
Bonanomi Professional Machining
For over 70 years, Bonanomi has stood out for its competence and professionalism among companies specialising in precision mechanics.
With a range of sophisticated and ultra-modern machine tools, Bonanomi provides precision machining for third parties, consulting services and a complete express shop with top-quality precision engineering products.