Before you can decide which type of drill bit to use for a particular job, you would want to first know their construction and recommended application. With this guide of drill bit types and their applications, you will always use the right drill bit for different applications.
Before we get into the drill bit types, we need to understand which materials are used to make the drill bits. The most common materials used in the making of drill bits include the following.
- Carbon steel
- High speed steel
- Cobalt steel
- Tool steel combined with carbide tips
- Solid carbide
Other than the tough materials used in making the drill bits, they will also have special coatings to make them better. The coatings will be made of black oxide, titanium nitride, and bronze oxide. The black oxide coating is the most common and economical.
It is important for protecting the drill bits against rust, relieving stress on the bit, and so much more. The same applies to the other coatings only that they are better.
Table of Contents:
Common Drill Bit Types
There are many drill bit types on the market right now. However, we want to look at the most common you are likely to encounter when looking for drill bits.
The twist drill bits must be the most common drill bits you will encounter in the market right now. They come with spiral patterns on them for drilling and removing debris from the hole they make in the material. The twist drill bits are ideal to be used on metal, plastic, timber, and related materials.
Such drill bits will either be made from high speed steel or carbon steel. The high-speed steel is good for drilling into many different materials and can stand up to the high temperatures. Carbon steel on the other hand is good for drilling wood and not metals. They are brittle bits and flex a lot more than high speed steel bits.
They are designed to have a hex shank to fit in most drill types. They are seen as ideal for drilling the pilot holes. They are however limited by the low power. You might not find them having many uses and thus they are limited in availability. Also, there is no much variety when it comes to screwdriver bits. The same cannot be said for twist bits mentioned above.
3. Masonry bit
It is easy to tell their application from the name of the bit. The masonry bits are commonly used for drilling into stones, quarry tiles, concrete, block, and much more. The cutting tip will be made from tungsten carbide and then coupled with a spiraled steel shaft. Some of the masonry bits will have a highly durable silicon bronze alloy for the tip.
These bits are commonly used in power drills. The aim is to have enough power so that the drill can go through the hard-concrete surface. If you need to sharpen the masonry bits, use a drill sharpener or sometimes a grindstone.
You might find the spur point bit also being referred to as wood or dowel bit. They are designed to have a central point and additional two raised spurs on the sides. The aim of these two spurs is to keep the drill bit drilling straight. It is advisable to use a power drill when working with a spur point bit. This is because it will leave a clean sided hole. Other than drilling wood, the same can be used for drilling plastics.
As for sharpening, use a fine file to sharpen the spurs and the central point at the front of the bit. Make sure that the angle between the spurs and central point is 90 degrees.
At first, you might mistake a bullet pilot point bit for a spur point bit, however, this type is designed to work on metal, plastics, and wood. Still as part of the design, the bullet pilot point will have twisted flutes that are ground away. The result is that you can now have a truer and more accurate drill bit as compared to the normal twisted bits.
You will find that they make clean holes and will cause little damage to the workpiece as compared to other bits you might use.
The countersink bits are essential for making a conical recess in the workpiece important for installing the countersink screws. They are designed to work on softer materials such as plastics and timber and not metal. Use a power drill to get the best results.
Some can come fitted with a handle. This allows you to make the recess in the holes by a hand twisting motion.
The variation to the countersink bits is the countersink bits with clearance drill. This combination is great as it can drill a clearance hole in combination with the countersink recess in just one go.
7. Tile bit
If you have to drill into ceramic tiles and glass, then you need the tile bit. It is built to have a tungsten carbide tip. The tile bit is commonly used with a hand drill or a power drill running at slow speed. When drilling in glass, use some form of lubricant such as white spirit or turpentine to help keep the tip cool.
The ceramic tiles can still be drilled by using a masonry bit, but the power drill should be running at the lowest speed and with no hammer action. The hammer action might split tiles.
8. Flatwood bit
The flatwood bit has a pointed center that guides the flat part to drill into the wood. It is designed to be used only in a power drill. The side will cut away the timber making a hole. These bits are commonly used for making large holes into the workpiece. Because of their design, they will leave a flat-bottomed hole in the piece.
If you have to use the large flatwood bits, then consider using a powerful drill so that it can push the drill into the timber. It is easy for you to sharpen this drill bit. You simply have to use a fine file, a grindstone, or an oilstone.
9. Hole saw
If you want to make large diameter holes in wood or plastic, then buy the hole saw bit. The bits can cut up to a depth of 18mm. You can get deeper versions, but they are not as common. If you want to achieve a smooth hole, then consider using a power drill at low speeds to get it done.
10. Forstner bit
The Forstner bit is designed to have a flat bottom. Because of this design, it is commonly used for working on kitchen cupboard hinges and other related applications. It is best if you use it with a power drill applying the right amount of pressure to get a smooth hole. If you use a freehand motion, it might be difficult to position and control it.
Drilling large diameter holes in wood or boards will require a special wood auger bit. You will find it commonly used in a hand brace. When used correctly, it will leave you with clean, deep, and flat-bottomed holes. Use a fine file if you have to sharpen the drill bit to make it work better.
12. Step drill bit
The step drill bit gets its name because of the design. Its design incorporates a stair like appearance. For this drill bit, you will find it ideal for drilling different hole sizes on a sheet metal. As much as a step drill bit can be pricey, it remains a versatile bit to own. The deeper you go, the wider the hole becomes.
Anyone who needs to drill holes in different materials could use all the information about drill bit types. We have looked at the most common options on the market right now for you to buy.
At this point, you have an idea where to use the different drill bits depending on the workpiece material. You can get a set with as many different drill bits as possible if you have to work on various projects more often.