Pour carry out DIY work and obtain a result that lives up to one’s expectations, it is essential to use equipment adapted to each task. The drills are no exception to the rule because they must be chosen according to the material to be drilledwood, metal, concrete, glass, tiles… Let’s see what are the criteria most importants to consider when choosing your drill bit.
Which material (material) should be drilled?
This is the first question to ask because material to be drilled will depend on the choice of drill bit. This is very important since each material has its own featuresin terms:
- Density,
- of hardness,
- Drilling resistance.
It is always necessary choose a bit harder than metal that must be pierced. It is an unstoppable logic since some drills that can drill an alloy will be totally ineffective on carbon. It is therefore to respond to all the problems that the drill is available in many models, grouped into two very distinct families:
- Alloy steel drill bits : this is also called thehigh speed steel. It is an alloy obtained thanks to the combination of a metallic element and a chemical element, the latter giving its specificity to steel.
- Carbide drills : it is a hard metal obtained by heating a powder either of titanium, cobalt or even carbon associated with tungsten (to give tungsten carbide). This manufacturing process makes it possible to obtain what is called a sintered compound.
Indispensable for the drill, the drill bit is a wick that comes in different models in order to drill a material without damaging it. It must therefore be chosen according to its composition. Thus, we find in DIY stores the drill bit perfectly suited to the work you want to do. the final result well and truly depends on the quality and type of drill bit used.
However, it should be noted that you can drill almost any type of material with a medium quality lambda drill bit, provided that it is perfectly sharpened. But more is needed adjust the rotation speed to the material to be drilled et use a lubricant (or cutting oil) suitable, this being essential to prevent premature wear of the drilling equipment. This is the type of information that a professional can give to his clients when they are about to choose a drill bit.
The different types of drill bits: a bit for every material
Each drill has a queue very specific in order to be perfectly adapted to a mechanical part called the mandrel because it allowsfitting the drill bit to the drill. The chuck is attached to the end of the rotary machine shaft. The shank of the drill can be:
- hexagonal : The hex shank bit is suitable for electric screwdriver or electric screwdriver. Its size is usually between 10 mm and 13 mm.
- fluted : this is what is chosen if the drill must be fitted to certain SDS chucks (Max or +)
- Smooth : this is suitable for a keyless chuck or a keyed chuck.
The shape of the drill (bit) is also variable. Thus, twist drills are found for drilling metals and concrete, and their spirals differ. They are what allow the evacuation of metal dust resulting from drilling. As for the wood bit, it is flat in addition to being helical.
Some drill bits are designed to work with delicate materialsas this is the case :
In this case, it is in your best interest to opt for a tungsten carbide drill bit or even a diamond drill bit.
Choosing a drill bit: what to remember
Here is a short summary of the different drill bits and the drilling materials they are suitable for.
To drill glass
High hardness glass-specific, conical and smooth shank drill bit, made of crystallized pure carbon called diamond.
For drilling tiles
Conical shape drill bit with smooth shank, in tungsten carbide. It can also be used to drill tile and ceramic.
For drilling metals
There are different metal drill bits, namely:
- Pour non-ferrous metals : metal drill bits, with smooth and hexagonal shank, in rolled steel or ground steel, in different manufacturing materials such as HSS, tungsten carbide and titanium.
- For’stainless steel : metal drill bit, with smooth and hexagonal shank, in cobalt.
- For any kind ofsteel : metal drill bit, with smooth and hexagonal shank, in solid carbide.
For drilling stone, blockwork, reinforced concrete, concrete
Concrete drill bit, with smooth shank, whose attack cut allows excellent penetration into the material (SDS Max or SDS+). The drill can be made:
- either in tungsten carbide: there are tips with 2, 3 or 4 cutting edges,
- either in carbide with tip also in very high quality carbide.
For drilling wood
Hexagon smooth shank wood drill, made of steel, with:
- Either a spiral bit for drilling lumber,
- Either a spade bit or a three-pronged bit for drilling carpentry wood.
Choosing a drill bit: other selection criteria not to be overlooked
Depending on the work to be carried out, when you need to obtain one or more drill bits to install on your drill, it is necessary to consider the following points:
Range
In top of the linewe find the solid carbide drill because it is able to drill deep into the hardest metals.
In mid-rangeyou can get high-speed steel drills but containing a certain rate of cobalt, such as HSS drills, which offer good value for money.
In entry level, are rolled drills and ground drills, knowing that the latter are suitable for regular use. They are therefore preferable to laminated drill bits.
The point angle
The greater this point angle, the more suitable the drill is for drilling hard metals. The point angle can be 90°, 120°, 135°, 140°, 145°. It is therefore exclusively according to the material to be drilled that the point angle is chosen.
The price of the drill
In this area, the range is considerable. For information, an entry-level drill is marketed at an average price of 15 to 18 €, a cobalt drill costs around 300 € in diameter 10 mm while a solid carbide metal drill sees its selling price climb to more than 750 or 800 €. We understand that this type of equipment should not be purchased lightly, without a needs analysis having been carried out beforehand.