A common challenge for contractors is choosing the right drill bit given different drilling conditions. Whether it’s plastic, wood, metal or concrete, every material that is drilled into offers a unique set of challenges. Regardless of the drill a contractor uses, drilling will only be efficient and accurate if the proper drill bit is selected for the job.
Today, there is an endless selection of drill bits available on the market. While the base of most drill bits is composed of high-speed steel, many specialized bits are combined and coated with a variety of different alloys. Having a better understanding of these performance characteristics will make it easier to select the correct drill bit for each job that comes your way.
Cobalt
Cobalt drill bits are manufactured with high-speed steel and five per cent cobalt in their composition. Due to cobalt’s hardness and high-heat resistance, these bits are particularly useful when drilling into hard materials like stainless steel and cast iron. Cobalt drill bits are the longest lasting and most durable products available on the market.
Titanium
Titanium drill bits are produced by coating high-speed steel with a thin layer of titanium nitride. The titanium coating increases the drill bit’s surface hardness, lowers friction coefficient and offers increased corrosion protection. These bits last longer than standard metal drill bits and are suitable for general applications, such as drilling through wood, plastic or metal. They also perform well on stainless steel.
Black and Gold
Black and gold drill bits are manufactured by coating high-speed steel in a combination of black and gold oxide. The design provides better rust prevention performance and offers a unique appearance that stands out from standard black oxide drill bits. These bits are also cost effective and designed for general applications.
Multi-Material
Multi-material drill bits are similar in construction to masonry bits, with a carbon steel body and brazed carbide tip. The main difference from a regular masonry drill bit is that a multi-material carbide tip receives special sharpening to drill through metal. The main advantage of the multi-material bit is that it can pierce through several materials simultaneously, including brick and concrete. These drilling conditions would ruin the tip sharpness of a regular metal drill bit, making this variety a necessity for heavy-duty applications.
Selection Tips
Choosing the wrong drill bit can result in workplace losses, such as ruining your workpiece or creating inefficiencies with multiple bits. Therefore, before beginning any project, it is crucial to identify the drilling conditions. Once this step has been completed, it will be easier to determine which variety of drill bit you should use.
Additionally, when buying drill bits, do not make assumptions regarding the composition of the bit based on appearance or price alone. Instead, carefully read the packaging and determine what metal the drill bit is made of so you can match it to the correct application.
For more information on different varieties of drill bits and their ideal applications, please visit your local Co-op Home Centre.
FAQs
Drill bits are classified by the materials they are manufactured from and the coatings applied to them. High-Speed Steel (HSS) drill bits are used for drilling wood, light metals, fiberglass and PVC. Black oxide-coated drill bits are more durable than standard HSS bits and the coating helps the drill bit resist rust.
How to tell which drill bit is for metal? ›
Metal drill bits have blunt ends without any protrusions so they grind through the material evenly. Material Metal drill bits tend to have a black or gold finish while most wood drill bits only have a shiny silver finish.
What drill bits are meant for metal? ›
The best drill bits for metal drilling in ascending order in terms of cost are High-Speed Steel (HSS) bits, Black Oxide bits, Cobalt steel bits, and Titanium bits. For drilling large holes in thin or soft metals, you can use a hole saw which can also be used with a cordless drill.
What setting should my drill be on for metal? ›
For example, if you're drilling an 8 mm hole in brass you should set your drill to a speed of 2500 r.p.m. Or for stainless steel, which is much harder, the right drilling speed is 800 r.p.m. A good sign that you're using the right speed is that you'll get nice long shavings.
What's the best drill bit for metal? ›
Cobalt drill bits are often the best for drilling into hardened steel. Whereas titanium drill bits only have titanium in the coating, cobalt bits have cobalt throughout. After cobalt drill bits get worn out over time, you can resharpen them.
Can any drill bit go through metal? ›
Here are a few tips for drilling neat and precise holes in metal. Choose the right bit for your metal. High-speed steel bits, commonly used for wood, are suitable for softer metals like aluminium. For drilling steel or other hard metals, use a stronger cobalt, titanium, or carbide bit.
Why won't my drill bit go through metal? ›
Regular drill bits can't cut through steel, so you need a heavy-duty, hard drill bit to do the job. But in a market full of options, what are the best drill bits for metal? There are two choice selections that you can count on to drill hardened steel in any of your metalworking projects: titanium and cobalt.
What Colour are drill bits for metal? ›
Gold drill bits are designed to drill into metal. Their gold colour comes from a titanium nitrate coating which slows down wear and tear. Drill bits without this coating are grey or silver, and their uses vary. For example, they may be multi-purpose or designed specifically to drill into wood or masonry.
How do you tell the difference between a metal drill bit and a wood drill bit? ›
Metal drill bits typically have a sharper and more pointed tip, while wood drill bits have a flat, paddle-like shape. Metal drill bits often have a black oxide coating, whereas wood drill bits may have a polished or coated surface to reduce friction.
Do you drill metal fast or slow? ›
The faster a bit spins, the hotter it gets. And heat dulls bits quickly. In general, it's a good idea to drill through metal using as slow a speed as possible using a drill bit for metal. Hard metals like steel and larger drill bits require even slower speeds.
The rule of thumb is to drill the hole with the same size drill bit. If you want a 1/4 inch hole, you use a 1/4 inch bit. Simple huh? If the hole is getting threaded later you look up the drill correct for the tap.
What degree drill bit is best for metal? ›
The two most common point angles for metals are 118 degrees and 135 degrees. The sharper 118-degree angle is best used for softer metals. Harder metals will wear the bit faster. The 135-degree self-centering point angle is flatter, putting more of the bit in contact with the substrate.
How do I choose a drill bit for steel? ›
1) Metal drill bits
Metal drill bits with a partially ground tip are suitable for non-ferrous metals. These include aluminum, copper, brass, zinc, iron and non-alloy steel. Drills made of cobalt-alloy High Speed Steel (HSS-E) or even drill bits with a titanium coating are needed for stainless steel.
What is the hardest drill bit for metal? ›
When it comes to drilling hardened steel, carbide drill bits are the champions. The carbide drill bit has exceptional hardness and resistance to high temperatures make them ideal for this task.
How do I know if my drill bit is metal or concrete? ›
Concrete is rock hard material that you can't just use any drill bit for. Concrete drill bits are blunt and have a blunt tip with wings that work like a chisel. The tip is made of extremely hard material, like tungsten carbide or widia (from the German wie diamond).
How do you recognize a drill for soft metal? ›
Quick helix drills or large helix angle drills, with a helix angle of 40° and a point angle of 100°, are suitable for drilling the softer materials such as aluminium alloys and copper.
How to tell if a drill bit is HSS? ›
Usually HSS Bits have HSS engraved on the shank together with the size of the diameter. An HSS bit is dark, almost black in colour compared to titanium coated or other type of coating. The cutting edge and the flutes of the drill bit look sharp and nice ground.
