Drilling various materialsDrilling is a science in itself. At least that might be the impression you get when you take a look at the drill bit selection in any hardware store
But as a DIYer it should be perfectly sufficient just to focus on a few types of drill bits when you're making a purchase. Although different drills are required for drilling different materials, many drills, such as metal drills, can be used universally. In this article we will try to shed some like on the range of drills out there and to explain which drills are best suited to which materials.
Drilling wood is certainly the standard for DIYers and takes up the majority of their regular drilling tasks.
With augers, the spiral is pronounced at a shallower angle. This makes it possible for the drill to remove the cuttings more easily. For this reason, the augers are particularly well suited for deep drilling. Augers are used particularly frequently by carpenters.
Forstner drills are used if holes need to be slightly smaller, for example for inserting concealed hinges in wall units or when creating cable ducts in desktops. As with wood drills, these also have a central drill bit and cut on the protruding edge. Above all, the Forstner drill looks different as it has an unusual shape compared to other wood drills.
Spiral wood drills
Wood drills are classic spiral drills with a highly pronounced central drill bit. This point ensures that the drill does not run as fast in soft wood and that the outlines of the hole are the first to be cut with its protruding, lateral cutting edges. As a result, the lateral fibres are cut clean and a tear‐free drill hole is formed.
If you find yourself wanting to drill a hole in plastic, you don’t need to buy a new drill. You can use any wood drill to drill plastic. Only when drilling at the speed is it recommended to use one of the lowest setting of the drill. The higher the speed, the more the contact surface between the drill and the material heats up. This results in a less attractive result, as the plastic melts.
When drilling metal, it is important to use an appropriate metal drill.
Step drills are used when it comes to expanding a hole in a piece of sheet metal. Step drills have a conical shape, similar to counterbores. Step drills do not drill downwards like conventional drills, but rather into the width using its tapered shape. When using a step drill, it is absolutely essential to pre‐drill a hole beforehand with a metal spiral drill. The step drill will then follow this hole and widen it.
Spiral metal drills
In contrast to wood drills, metal drills do not have a central drill bit. When drilling steel this would quickly snap and due to the low contact surface it would overheat and then burn up. Metal drills are also spiral drills. However, they have a carbide cutting edge, often called HSS.
If you do not have a wood drill to hand, it is not a big deal if you grab a metal drill instead. Wood and metal drills are very similar in shape. The most noticeable difference is that metal drills have a less prominent central drill bit and a different cutting angle.
Stone drills of course come into play when it comes to drilling stone. When purchasing stone drills it is important to ensure you have the right drill for the shaft. If the drill or drill hammer has an SDS plus shank, drill bits with round shanks will not fit. And the same applies vice versa!
Core drill bits
When it comes to larger holes, such as when installing sockets or drilling a chimney connection, a normal stone drill is no longer enough. This is when core drill bits are used. A core drill bit is formed like a bell, in the centre of which a centre drill is inserted. The centre drill ensures that the core drill bit does not slip. The core drill bit carries out the drilling work. If you take a closer look, the core drill bit does not drill, but rather saws. Core drill bits are available in different sizes and for different tasks. However, larger core drill bits can only be used by specialised drills.
Spiral stone drills
Stone drills are also spiral drills with a carbide drill bit. This carbide drill bit is soldered to the drill in the brazing process. As carbide is much more expensive than steel, stone drills only use carbide drill bits. A carbide cutting edge, as used with metal drills, would become dull within a few seconds when drilling stone.
Most DIYers now tend to shy away from drilling holes in the bathroom and instead use adhesive products from the „gluing instead of drilling“ section. However, with the right drill, even drilling ceramics is no longer a problem.
Tile drills have industrial diamond‐edged drill bits. Note that these are industrial diamonds. Your spouse probably won’t be very happy with a diamond drill for Valentine’s day! When drilling ceramics and tiles it is important it is important to avoid the impact of a hammer drill.
For all holes in the wall, it is necessary to check whether cables are laid at the desired location before you start drilling. For this purpose, the trade offers so‐called locating devices, with the help of which electricity, gas and water pipes can be detected several centimetres deep. Nothing is more annoying than when the new shelf is electrified or water flows from the family photo on the wall!