16 Different Types of Drill Bits Explained

Different Types of Drill Bits
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A drill bit cuts a hole into a material like wood or concrete. The type and size of the drill bit will determine how deep the hole can be drilled, which affects the depth at which the screw can be inserted.

Choosing the correct drill bit is crucial to ensure maximum performance. This article provides guidance on the types of drill bits for each function. 

What is a Drill Bit?

A drill bit is a tool used to cut holes in wood or metal. Many kinds of drill bits are available depending on what you want to do.

They come in various shapes and sizes and have different functions. For example, drill bits are specifically for drilling through hard surfaces, while others are made for soft materials like wood.

Some drill bits are even made to fit specific tools.

Materials Used to Make Drill Bits

Regardless of the type of drill bit, they consist of similar materials used in making them. Here are a few materials used in making drill bits.

High-Speed Steel 

High-speed steel (HSS) is one of the common types used in the manufacturing process of drill bits.

Its high-speed tool steel contains elements such as molybdenum, tungsten, nickel, cobalt, copper, manganese, silicon, sulfur, and phosphorus.

However, most drill bits use either carbide or cemented carbides as cutting surfaces.

Carbide drill bits are typically more complex and robust than cemented carbide bits and are recommended for softer rock and concrete applications.

However, people prefer the HSS bits because they offer better performance under challenging conditions.

Carbide-Tipped

As mentioned earlier, carbide is solid. While many believe that carbide bits are just used in mining operations, that is untrue.

Manufacturers use carbide bits to cut concrete, wood, steel, and fiberglass.

Because of their strength, carbide bits can withstand extreme temperatures and pressures.

As a result, drillers can operate their equipment at much higher speeds without fear of breaking off the tip.

This allows drillers to reach deeper levels of rock formations and extract more significant amounts of oil.

Cobalt

The most versatile material in existence is cobalt. Its properties make it perfect for various industries, including aerospace, automotive, electronics, energy production, and medical devices.

Coating

The black oxide-coated bit is the most common type of drill bit. This type of bit keeps the bit cool during drilling.

In addition to keeping the bit cooler, it also keeps the bit cleaner. Black oxide coated bit also drills softer materials such as wood, plastic, fiberglass, concrete, etc.

Another type of coated bit is the TiN-coated bit. These types of bits drill more complex materials like steel, copper, brass, and stainless steel. 

Different Types of Drill Bits

1. Twist Drill Bits

Twist drill bits are the first on our list of drill bit types. They cut holes in rigid materials such as stone, concrete, ceramic tiles, metal, and wood.

However, people also use them to drill holes in soft materials like plastics, rubber, leather, and paper.

Twist drill bits make clean holes and consist of thin metal rods and high-speed steel.

Drillers use them in drilling applications such as boring, reaming, countersinking, and threading.

For instance, they are widely used in woodworking, plumbing, construction, and automotive industries.

2. Brad Point Drill Bits

Brad points are one of the most versatile drill bits around, and you can use them to drill into wood, metal, plastic, and even concrete.

They come in different sizes and shapes, including straight, angled, and triangulated. If you want something specific, like a pointed tip, you can buy it separately. 

Brad points drill into hard materials like concrete, brick, masonry, tile, stone, and metal.

They come in 3/8 inch to 2 inches and feature a unique design, allowing them to penetrate material without causing damage to surrounding areas.

This helps prevent the wastage of material and saves money. 

3. Flat Drills

Flat Drills are also among the types of drill bits; they make clean holes in materials like wood, plastic, and rubber.

They usually consist of a thin piece of steel and a sharpened tip. People also call these tools hole saws, cutting metals into small pieces.

They are famous in many industries, such as construction, plumbing, electrical, automotive, aerospace, shipbuilding, machine shops, and many others.

Again, people use flat drills to cut off the unwanted parts of a larger object. For example, they can remove the part of a wooden board you want to keep.

4. Masonry Drill Bits

Masonry bits make minor stone, brick, cement, or concrete cuts. They come in different sizes, shapes, and lengths.

You can buy them individually or in sets ranging from ¼ inch to 2 inches in diameter. Most people prefer larger drills because it makes drilling easier.

It would help if you always started with smaller bits to ensure you don’t damage your masonry work. Once you finish drilling, you can switch over to bigger bits.

5. Center Drills

A center drill is another drill bit among the types of drill bits. People call it a combination drill because it combines countersink and drill bits.

Also, it works well for fastening metal into wood and plastic. The center drill has a long handle with a small chuck attached to one end, and the kit usually has three different sizes of drills.

The larger size works for holes up to 3/4 inch wide, while the smaller size suits countersinks and pilot holes.

This drill helps make holes in wood, metal, plastic, glass, etc. In addition, it can also create holes in soft materials like rubber, leather, foam, and many others.

6. Spade Drill Bits

The spade drill bit is one of the most versatile pieces of equipment you can use in woodworking.

These bits come in many sizes and shapes depending on your work type. Also, you can buy spade bits in sets or individually.

A set usually includes 3 to 5 different sizes of bits for drilling holes in wood.

If you want to make a hole in hardwood, it is best to go with a larger size bit, like a 7/8″ or 1″ bit. For softwoods, you can use smaller bits like 2″ or 3/4″.

You can find spade bits in hardware stores, home improvement centers, online retailers, and specialty shops.

There are several spade bits, including straight bits, chisel bits, and hollow points. 

Straight bits are great for boring holes in wood without much tear-out. Chisel bits are ideal for cutting grooves into the wood.

However, hollow points cut through material quickly while minimizing damage to the surrounding area.

7. Shell Drills

Shell drills are among the types of drill bits and the most important drilling tools in the drilling machine industry.

They are widely famous for boring holes in rock and concrete and consist of four flute kinds: the lower part, the upper part, the middle part, and the sleeve part.

In addition, there are three types of shell drills according to the different shapes of the upper part: the tapered shell drill, the flat shell drill, and the hollow shell drill.

The tapered shell drill works for small-diameter holes, while the flat shell drill is suitable for large-diameter holes.

However, the hollow shell drill cuts off the surface layer of rock and cement block, and you can combine it with other tools such as reamers, core bits, etc.

8. Auger Drill Bits

Auger bits are among the most versatile types of drill bits. They come in many sizes, shapes, and designs.

Some double up as saw blades, making them great for creating large holes in hardwood floors, concrete, masonry, brick walls, and much more.

The best thing about auger bits is that they don’t require a lot of force to start drilling. This makes them perfect for drilling into dense woods like oak, maple, and mahogany.

You won’t need to exert too much pressure while drilling into these materials, making it easier on your joints and body.

9. Spirec Drill Bits

The Spirec Drills, which are excellent precision drilling tools, are mainly used in precision machining.

These precision machinings include manufacturing optical components, aerospace parts, and medical equipment.

Also, they produce high-precision products and can drill holes with diameters ranging from 0.08mm to 3.2mm.

These tools are also suitable for DIY projects; they are easy to use, safe, reliable, and durable. In addition, they do not require lubrication.

10. Rivet Drill Bits

Rivet bits are another type of drill bit used to attach pieces of sheet metal. They come in many different sizes and shapes, but most are cylindrical.

And a typical riveting job involves drilling holes into one piece of metal and inserting screws into those holes, which are then tightened against another piece of metal. 

The problem with traditional rivets is that you have to use a hammer to pound them in place.

These tools aren’t exact, and ensuring each hole is appropriately aligned takes a lot of effort.

The finished product could look rough if you don’t do it correctly.

11. Cobalt Drill Bits

Because of their popularity, cobalt drill bits have to be among the types of drill bits.

Cobalt drill bits are made from steel or stainless steel and are available in many sizes, shapes, and styles.

Most cobalt drill bits cut through various metals and alloys, including aluminum, brass, copper, iron, lead, nickel, silver, tin, titanium, zinc, etc.

They’re also ideal for woodworking because they can effortlessly bore through softwoods like pine, fir, spruce, cedar, and hemlock.

You can even use cobalt drills to make holes in concrete and stone.

12. Forstner Drill Bits

A Forstner drill bit is useful for woodworking and home improvement projects. However, it’s specifically for drilling into hardwood like oak, cherry, maple, and mahogany.

They come in different sizes, some of which include 3/8″, 5/16″, 7/32″, 9/64″, and 11/128″.

The best way to use a Forstner drill bit depends on what you’re doing.

If you’re working with softwoods, such as pine, fir, cedar, and cypress, it’s recommended that you insert the bit straight down into the material.

This allows the bit to cut through the material without tearing the surface.

Keep the bit perpendicular to the surface to ensure that you don’t tear up the surface.

However, start with a pilot hole if you’re working with hardwoods. A pilot hole is simply a small one that guides the larger one that follows.

Once you’ve drilled the pilot hole, you’ll know exactly where to place the bit to avoid damaging the surrounding area.

13. Installer Drill Bits

Installer bits are used for drilling through walls and ceilings for security systems and entertainment applications.

They look like an auger-type drill bit and work for installing wiring and cables.

These bits are up to 20 inches long and work well on brick, concrete, drywall, plaster, wood, and tile.

14. Countersink Bits

Countersinking is one of those things that seems like it shouldn’t work—until you try it.

A countersink bit is among the notable types of drill bits used to make a small recess on the surface of a piece of wood.

This allows you to use a router or jigsaw to cut out the area where the screw will go, as you don’t want to drill too far down because you risk ruining the bottom of the board.

A countersunk bit has a straight shank that goes through the wood.

When you drill a countersunk hole, you’re drilling a hole in the center of the wood. Then, you cut around the outside edge of the hole to expose a flat surface.

If you drill a countersunk/counter sunk hole, you start with a countersink bit, then switch to a larger bit to finish the job.

15. Hammer Drill Bits

A hammer drill bit is another drill bit that drills concrete, masonry, and metal.

This tool uses a steel head attached to a rotating shaft powered by a motor, and it’s usually replaceable.

The bits cut a circular hole in the material being drilled; however, some models include a straight edge, which allows for cutting along the length of the piece being drilled.

Also, some bits work with a pilot bit, which cuts a larger diameter hole to ensure a smooth transition.

Depending on what kind of work you want, there are many different hammer drill bits.

For example, hammer drill bits are specifically for drilling deep holes, cutting out large areas, and creating small holes.

Some even have special tips for working with certain materials, such as wood or tile.

16. Plug Cutter

A plug cutter is the last on our list of types of drill bits; it’s a handy tool for anyone working with wood.

This device drills out small pieces of wood to cover up exposed screws, bolts, nails, etc., making working around those pesky fasteners easier without damaging surrounding materials.

They come in different sizes and shapes depending on what you want to do. Also, you can use them to make custom handles, picture frames, drawer pulls, door knobs, etc.

Conclusion

Drilling is a great way to get into DIY projects, but the many types of drill bits available can be overwhelming.

We hope this article helps you choose the right type of drill bit for your project.

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