How to Save Money When Buying what kind of drill bit for steel
Best Drill Bits for Metal in - Pro Tool Reviews
Metal drilling is common, but since metal varies widely, so do the drill bits you should use. In this article, I’ll share the best drill bits for metal that we’ve used and recommend. I’ll also share the most important things to consider as you’re looking for the right bit to drill through soft metals like aluminum, hardened metals, and stainless steel.
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Best Drill Bits for Metal – Our Top Recommendations
- Hardened Metal and Stainless Steel: Drill America D/A Series M42 Cobalt
Jump to this Bit ↓ - Steel: Milwaukee Red Helix Cobalt Drill Bits
Jump to this Bit ↓ - Aluminum and Copper: DeWalt Pilot Point Titanium Drill Bits
Jump to this Bit ↓ - Step Bits: DeWalt Titanium Nitride Step Bits
Jump to this Bit ↓ - Rebar: Diablo Amped Rebar Demon Bits
Jump to this Bit ↓ - Metal Hole Saws: Milwaukee Hole Dozer Carbide Hole Saws
Jump to this Bit ↓ - Best for the Money: Bosch M42 Cobalt Bit Sets
Jump to this Bit ↓
Need Some Help Before Deciding? Jump to These Sections to Learn More!
- Metal Drill Bit Terms and Parts to Know
- Types of Drill Bits for Metal
- Why You Can Trust Pro Tool Reviews
Best Drill Bit Set for Hardened Metal and Stainless Steel
After head-to-head testing in multiple materials, we selected Drill America’s M42 cobalt bits as our best drill bits for hardened metal and stainless steel.
Manufactured according to National Aerospace Standard 907, the bits feature a 135° split point, which gives you a nice, steady, and productive drilling speed with less walking at startup.
Of course, it’s the quality of the M42 cobalt blend that gave these bits impressive drilling performance and life compared to the other bits we tested. You can drill up to 30% faster than you can with conventional M2 high-speed steel bits. It also holds its edge better when you’re drilling into hardened metals, stainless steel, or even titanium. That showed in our tests, where these bits seemed to melt through whatever we threw at them and then asked for more.
While the jobber length is tempting to use in cordless drills, remember that the harder M42 blend is also more brittle. Keep a steady hand when you’re drilling into metal to avoid snapping them.
Best Drill Bits for Steel
When considering the best drill bits for general steel drilling, the more affordable M35 cobalt is an attractive option. Balancing price and performance, we’ve had excellent success with Milwaukee’s Red Helix cobalt bits, and they’re our go-to bit for metal drilling with a cordless drill.
There are a few things that stand out in the design:
- Quad Edge Tip: Starts cutting faster and helps keep the bit sharp longer
- Variable Helix Flute: 35° – 15° flute angle reduces heat buildup and improves debris removal by 30%
- Tapered Web (core): Strengthens the bit against breaking
Since these are cobalt bits, you can sharpen them. However, using something like a Drill Doctor will reduce the effectiveness of the Quad Edge tips and can eventually remove them altogether. You’ll still have a quality cobalt bit—it primarily just loses some of its starting speed.
Another trade-off is that these bits thin out more towards the tip. Milwaukee countered this by making them a bit shorter than some others we’ve seen while extending the flutes further up the shaft. The result is a more compact bit with a similar drilling depth.
You can use these bits in any steel, including hardened and stainless. They’ll need sharpening a little sooner than M42 cobalt bits, but they’re more forgiving in handheld drills.
Best Drill Bits for Aluminum, Copper, and Soft Metals
While cobalt is the way to go for hard metals, I like titanium options as the best drill bit for aluminum, copper, and other soft metals. The coating lasts much longer and its higher lubricity makes quick work of these metal-drilling applications.
When you first look at DeWalt’s Pilot Point titanium bits, it’s understandable to be skeptical since the tip design is so different. However, when we tested it against other popular titanium bits, it proved to be the fastest—by a lot.
Even though the set is more expensive than standard titanium bits, it’s not a huge premium, and the performance gains are worth spending a few extra dollars.
Best Step Bits for Metal
Choosing the best step bit requires you to choose between speed and service life. With the way Pros, especially electricians, use these in the field, speed is usually the higher priority. With that mindset, DeWalt’s titanium nitride step bits are my top choice.
There are a couple of design elements that kick it up higher than other step bits we use. First, the titanium nitride coating is better at reducing friction and heat buildup on starts. Lower heat keeps the metal from hardening, so holes start quicker, and the titanium coating lasts longer than you might expect.
These bits also have two cutters with a curved flute. Compared to single cutters and straight flutes, DeWalt’s design works faster and holds its edge longer.
If you want the longest bit life, cobalt is your best bet. They can be a little harder to find, but we’ve had excellent results using Milwaukee’s and Greenlee’s cobalt step bits.
Best Drill Bit for Rebar
Sometimes, you need to drill through steel…but that steel is buried in concrete. When you’re drilling through reinforced concrete, the best drill bit to get you through rebar is Diablo’s Amped Rebar Demon line.
This is an upgrade of the Rebar Demon bits we’ve recommended in the past. It keeps the high-performance 4-cutter carbide tip and adds vacuum capability. When you’re drilling for chemical anchor installations, you can drill and remove debris in one step. It’s much faster than the drill-blow-vac-blow technique you normally have to use.
If you don’t need the dust collection function, go with Diablo’s standard Rebar Demon bits to get the same cutting performance at a lower price.
What we like about Diablo’s design is that all you have to do is drill. With designs like Bosch’s Rebar Cutters, you drill using rotary hammer mode with a standard bit until you hit rebar, switch to the Rebar Cutter in rotary-only mode to get through the metal, and then return to your original bit to finish the hole.
Diablo’s design drills quickly through concrete and then keeps chewing right through rebar. You don’t have to change bits, saving you a significant amount of time on each hole that adds up over the course of a job. It’s a huge win in our book.
Best Hole Saws for Metal Drilling
Traditionally, bi-metal hole saws were the top choice for drilling large holes in metal. Carbide is now king, though, and Milwaukee’s Hole Dozer with carbide teeth is the best hole saw for metal drilling that we’ve used.
It can tackle stainless steel and certainly anything softer or milder than that. Because they work effectively in both metal and wood, any Pro looking for a general-purpose set of hole saws should quickly fall in love with their productivity.
That said, Milwaukee’s Big Hawg hole saws are purpose-built for wood drilling and work faster if you’re not cutting in metal that often.
Carbide is an upgrade, so these hole saws are more expensive than bi-metal. However, the life is much longer. If you consider that one carbide Hole Dozer can replace dozens of bi-metal hole saws over its useful life, you come out way ahead.
Best Metal Drill Bits for the Money
When it comes to finding good value for metal drilling bits, it’s tempting to look to titanium or something like Spyder’s Mach Blue bits. They can be effective in some metals, including mild steel. But if you’re like me and come across hardened steel, even on occasion, cobalt is still the way to go.
Bosch has a set that’s in a similar price range as cobalt bits from other power tool brands but has one big advantage—they’re M42 cobalt, not M35. With a 15-piece set around $41 and a 21-piece set around $73, they’re more affordable, and you avoid the risk of a no-name Amazon brand without breaking the bank.
The 15-piece set covers 1/16 to 1/2-inch bits. Spyder’s Mach Blue set (~$35) only goes up to 3/8-inch and is a 10-piece set. With Bosch, you get more bits, a wider range, M42 cobalt, and only pay about $6 more for the set. That’s the kind of value that gets my attention and why Bosch earns my vote as having the best metal drill bits for the money.
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More Metal Drill Bit Recommendations from Brands We Trust
Diablo Impact Strong Step Bits
Diablo has a tempting step bit set that pulls in some of the best features with a price tag that got our attention. Made from high speed steel (HSS), their split point tip reduces walking and starts fast, while the dual-flute design keeps the feed rate high in thin metals. Plus, they have an impact driver-friendly 1/4-inch hex shank.
You’ll want to stick to typical electrical, HVAC, and plumbing applications, though. The bits struggle as you move into thicker and harder metals.
Price: $109.99 (3-piece set)
Greenlee Cobalt Step Bits
If you’re looking for cobalt step bits for their longer life, take a look at Greenlee. Their Made in the USA cobalt step bits feature a split point tip that gets holes started notably faster than others and a dual flute design that keeps the cutting speed high. Plus, a steam oxide finish helps these bits last longer than others. It’s the best balance of speed and service life we’ve seen.
The downside is that these premium bits are more expensive. A 3-piece set that includes #1, #3, and #8 sizes is $215.99.
Price: $215.99 (3-piece set)
Irwin Cobalt Industrial Drill Bits
Irwin’s M35 cobalt industrial drill bits are a solid choice if you’re looking to save some money or need a quality index set for use with handheld drills. At $130 for the 29-piece set, it covers 1/16 – 1/2-inch sizes and is notably less expensive than M42 bits.
The larger bits have a small shank size, so they’ll still fit in 3/8-inch chuck drills. That’s perfect for electricians, HVAC techs, and others who have to drill through metal but prefer lightweight, compact drills.
It may seem like a small thing, but the set comes in a durable metal case with slots that the bits slide in and out of easier than other designs we’ve used.
Price: $129.99
Makita Impact Gold Titanium Drill Bits
Makita makes a quality set of titanium bits that push all the right buttons for metal drilling, but it’s what you can’t see that sets them apart. As part of the Impact Gold lineup, they’re specifically designed to withstand the violence of drilling with an impact driver better than other titanium bits. If you drill with your impact driver often, keep a set of Makita Impact Gold drill bits in your tool box.
Price: $22.99 (14-piece set)
Ryobi 1/4-inch Hex Titanium Drill Bits
While we clearly prefer cobalt, titanium bits have their place for metal drilling, especially when hardened metals and stainless steel aren’t your norm. For general tasks and projects around your home, Ryobi’s 22-piece titanium bit set will take care of nearly everything you’ll run into.
This set covers 1/16 – 3/8-inch sizes and the bits have 1/4-inch hex shanks so you can use them in either a drill or impact driver.
Price: $19.97 (22-piece set)
Spyder Mach-Blue Drill Bits
Spyder’s flagship drill bits have what they call Mach-Blue Armor Plating covering an M-series HSS bit. Details of the outer coating’s chemistry are a trade secret, but the claims are impressive—up to 100x more holes and 8x faster than titanium or black oxide. We’ve noticed the speed difference in our own tests, though we couldn’t find any volunteers willing to see if they could actually drill that many more holes than our favorite titanium bits.
What makes these a tough call isn’t the quality or performance but the price. At roughly $36 for a 10-piece set (1/16 – 3/8-inch), the price tag is similar to cobalt bits. However, these are Made in the USA, and combined with their extreme life, makes them worth a shot, especially if you don’t deal with hardened metals that often.
Price: $34.99 (10-piece set)
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Metal Drill Bit Terms and Parts to Know
Twist Bit
A twist bit is what most people think of when you’re talking about drill bits. Its tip is usually 118° or 135° and tapers very quickly to the flutes, where it has a straight profile until it reaches the shank. While the scope of this article is on metal drilling, they’re also good for wood and plastics, and some have tips specifically for concrete and brick.
Split Point Tip
Many drill bits for metal have a split point tip. At the very tip, there’s a smaller extra set of cutting edges that help start a hole before the main cutting edges engage the material. This is an incredibly helpful feature for metal drilling because it helps prevent the bit from walking (sliding around) as you try to get the hole started and helps it drill faster as the bit progresses through.
Flute
Flutes are the channels that spiral around a drill bit. As the bit’s cutting edge removes material, the debris moves along those channels until it reaches the top of the hole and escapes.
Step bits also have one or two flutes. Unlike twist bits, they can be straight or sometimes have a gentler spiral.
Shank
The shank is the top section of the bit where you connect it to your drill or drill press. Some designs leave the shank round, while others have a 3-flat grind. Grinding flats on the shank gives it three flat edges that the teeth of your drill’s chuck can hold more securely.
Having a 3-flat grind isn’t as big of a deal for use with a drill press since they typically have a keyed chuck. However, it’s very helpful for the keyless chucks on cordless drills.
You can also find metal drill bits with a 1/4-inch hex shank. These fit in both drills and impact drivers
Web
Underneath the exterior of a drill bit is a core material called a web. Piercing into the bit with a narrow V shape that tapers down to the tip, it forms the chisel at the very center and strengthens the bit, making it harder to snap.
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Hole Saw
When you need to drill a large hole in metal, twist bits are impractical, and a hole saw is the better tool. As its name suggests, it’s a type of saw that cuts a hole. The saw’s teeth surround the edge of a metal cup and cut into the material as your drill spins it.
Unlike a twist bit that removes all the material as it makes a hole, hole saws cut out a core that’s left inside the saw’s cup that you have to dig out. It’s a little bit of a pain, but when you consider that twist bits can only drill up to ~1/2 an inch in metal, and a hole saw can drill up to a 6-inch hole, it certainly has its place.
The advantage of using a hole saw is price. The cost to make a drill bit that removes all the material requires a much more robust build and longer cutting edges that would be prohibitively expensive.
Step Bit
A step bit is a common tool electricians, HVAC techs, and plumbers use to cut through thin metal. They can also be helpful in some wood and PVC applications.
They get their name because they progressively cut a wider hole in steps. Once the tip starts the hole, each step after that continues to widen it.
What’s nice is that each step has a specific measurement, so you’re able to cut multiple hole sizes with one bit. You just have to know which step to stop at if you need a precise hole size.
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Best Types of Drill Bits for Metal
There are many types of drill bits made with a diverse number of coatings and compositions. Complicating things, not all bits of the same type are equal. Small differences in the blend of titanium coatings or cobalt blends affect how bits drill through metal. When it comes to the best drill bits for metal, however, there are some general principles that can keep you on the right track.
Avoid These Types of Bits for Drilling Steel
Perhaps the best place to start a discussion about drill bits for metal is to highlight what not to use.
Avoid any low-carbon steel blends. While inexpensive, they don’t hold a sharp edge for long against metal.
Generic and cheap high-carbon steel bits are on our no-go list as well. Upgraded materials might make these better than low-carbon steel, but impurities in the blend quickly degrade the cutting edges when drilling metal or, worse, make them break more easily.
Black oxide bits are popular and inexpensive, but they’re best left to wood and plastic drilling. While the coating provides some corrosion and heat resistance, drilling into metal quickly dulls the cutters.
Finally, avoid drill bits with brad points. Their relatively tall, sharp points are great for starting a hole in wood, plastic, and other soft materials. However, they quickly wear down or break off on harder metals.
High-Speed Steel (HSS)
High-Speed Steel (HSS) drill bits present an upgrade over older carbon steel bits. Able to hold up better to excessive heat and wear, they make up the majority of drill bits sold on the mass market.
You can use these bits for just about anything, serving as a jack-of-all-trades for both wood and metal applications. HSS can be temperamental, losing performance and dulling if you use them at the wrong speed for the metal you’re drilling into. With the speed properly set and using some drilling oil, they’re an excellent choice to pair with your drill press. Plus, you can sharpen the cutting edes and bring them back to life when the time comes.
Titanium Coated Drill Bits (TiN or TiCN)
Drill bits made with a Titanium nitride coating resist corrosion and friction. It beats black oxide because it increases surface hardness and does a better job reducing heat while drilling through metal. For metal drilling, we recommend these as the bare minimum.
With titanium nitride bits, remember it’s a coated bit. As the coating wears off the cutting edges, you lose the advantages. It’s possible to sharpen them, but you only have the benefit of the core steel since the titanium no longer coats the edges.
When you’re drilling metal, these bits do their best work in softer blends like aluminum and mild steel. While you can use them for drilling hardened steel or stainless, they won’t last as long.
Mach-Blue or Titanium Nitride and Aluminum (TiAlN) Coated Bits
Spyder uses a proprietary Mach-Blue plating on its drill bits. Likely a form of Titanium Nitride and Aluminum (TiAlN) coating (the actual chemistry is a secret), it helps retain sharp cutting edges and reduce heat build-up. According to Spyder, the coating achieves faster cuts and significantly extends the bit’s life compared to standard titanium coatings.
Spyder uses heat-treated M-Series tool steel underneath its Mach Blue coatings, and they’re Made in the USA.
Cobalt Steel Blend
Cobalt drill bits are our go-to for drilling hard metal. As an additive, cobalt strengthens the steel blend so that it’s able to hold up to drilling hardened and stainless steels. Plus, it’s a blend, so you can sharpen these bits and have the full benefit of the chemistry.
There are some differences in cobalt blends, though. It starts with the quality of the core materials and extends to the percentage of cobalt the blend uses.
M35 vs M42 Cobalt
Our choice when it comes to the best Cobalt drill bits for metal drilling is made from a blend of 8% cobalt (M42). Other popular options use a 5% cobalt blend (M35).
M42 cobalt bits are harder, so they’re able to cut through hard materials more effectively. However, they’re more brittle and easier to break, especially with smaller sizes.
M35 cobalt bits aren’t quite as hard but are still capable of drilling hard metals. Since they’re not as brittle, they’re the go-to choice for use in handheld drills. They’re also less expensive than M42 bits.
Need a drill bit sharpener? Check out our review of the Drill Doctor 750X drill bit sharpener.
Drilling Into Hardened Steel
When we talk about drilling in hardened steel, we mean medium or high carbon steels typically made using a heat-treatment and tempering process. Hardened steels are durable and can be wear-resistant, corrosion-resistant, and abrasion-resistant. Many of the steel materials we see in mechanical engineering, energy generation, and transportation are some form of hardened steel.
When you’re drilling into hardened steel, we recommend using high-quality cobalt bits. Go with M42 if you’re using a drill press or M35 if a handheld drill is your tool of choice.
Drilling Into Stainless Steel
Stainless steels are steel alloys consisting of at least 10.5% chromium and there are different grades. As a low-carbon steel, stainless steel has a natural hardness that comes without traditional hardening techniques. Because of rust and stain resistance, good luster, and low maintenance, it has many commercial uses including cookware, cutlery, home appliances, construction fasteners, and surgical instruments.
This type of steel can actually harden as it heats, so when you drill through stainless steel, go slow to get through the material more efficiently. Use cutting oil as you drill and apply only enough pressure to see a steady removal of material.
Like hardened steel, stainless steel is quite difficult to drill into, and our bit recommendation is the same. Use a drill press with an M42 cobalt bit for the best results, or go with an M35 cobalt bit if you’re using a handheld drill.
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Disagree With Our Choices?
That’s okay! We know personal preferences take a front seat in determining the best drill bit, and every Pro is different. Do Pro Tool Nation a favor and tell us what your top pick is and why you love it. Feel free to put it in the comments below or on Facebook, Instagram, and Twitter!
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Drill Bit Selection Guide: Types, Uses, and Maintenance - tradesafe
Drill Bit Selection Guide: Types, Uses, and Maintenance
One of the most important tools in any metalworker's arsenal is the drill bit. Drill bits are cylindrical cutting tools that are used to create holes in various materials such as metal, plastic, wood, ceramic tile, and concrete. But not all drill bits are made the same, and choosing the wrong one can lead to disastrous results.
Using the wrong bit can result in damage to the material, decreased efficiency, and even injury to the user. Therefore, it's essential to understand the various types of drill bits available and their unique features, including materials, coatings, point angles, and lengths.
Whether you're a seasoned metalworker or just starting, this guide will equip you with the knowledge you need to make informed decisions and achieve the best results.
Drill Bit Materials
Here are the three most common types of drill bit materials:
High-Speed Steel (HSS)
High-speed steel (HSS) is a type of tool steel that is highly resistant to heat and wear. It contains tungsten, molybdenum, chromium, and vanadium, which provide increased strength and durability. HSS drill bits are suitable for drilling into soft metals, such as aluminum and brass, as well as wood and plastic.
- Advantages: HSS drill bits are relatively affordable, easy to sharpen, and have a long lifespan when used correctly.
- Disadvantages: HSS drill bits are not suitable for drilling hard metals, such as stainless steel, and can lose their sharpness quickly when used on tough materials.
Cobalt (HSCO)
Cobalt (HSCO) drill bits are made from high-speed steel with added cobalt, which enhances their strength and heat resistance. They can withstand higher temperatures and are less prone to dulling. Cobalt drill bits are ideal for drilling through hard metals, such as stainless steel, cast iron, and titanium.
- Advantages: Cobalt drill bits are highly durable, resist wear and tear, and maintain their sharpness for longer than HSS drill bits.
- Disadvantages: Cobalt drill bits are more expensive than HSS drill bits and require specialized equipment for sharpening.
Carbide (Carb)
Carbide (Carb) drill bits are made from tungsten carbide, which is a dense and durable material that can resist high temperatures and wear. They are ideal for drilling through hard materials, including ceramics, glass, and masonry, as well as hard metals like stainless steel and cast iron.
- Advantages: This type is incredibly durable, can maintain its sharpness for longer than other drill bit materials, and can handle high-speed drilling.
- Disadvantages: They are the most expensive of the three materials, and they can be brittle, which can cause them to break if they're not used correctly.
Design Features of Drill Bits
To choose the best drill bits for metal and other materials, you should consider the design features that affect their performance. These are the three key design features of drill bits:
Drill Point Angle
The drill point angle refers to the angle at which the cutting edge of the drill bit is ground. It is measured in degrees and can range from 90 to 150. A 118-degree angle is the most common, but other angles, such as 135 degrees and 90 degrees, may be more suitable for specific materials or applications.
Common Drill Point Angles
- 118°: Most commonly used angle for general-purpose drilling in metal, wood, and plastic. It is ideal for drilling softer metals, such as aluminum and copper. It also offers a balance between sharpness and durability. However, it may not perform well on harder materials.
- 135°: Better suited for drilling harder materials and alloys such as stainless steel, cast iron, and titanium. While it can handle harder materials, it may not be as effective on softer ones.
- 90°: It is used for creating countersink holes, deburring, and chamfering, but not suitable for drilling.
Drill Point Lengths
The drill point length refers to the distance from the tip of the drill bit to the beginning of the flute. There are three types of drill point lengths: standard, jobber, and long.
- Standard: Offers the most rigidity and is best suited for shallow holes in softer materials. Since it is rigid, it may not be suitable for deeper holes.
- Jobber: A versatile length that can drill holes of various depths and range of materials and is suitable for general-purpose drilling. While versatile, it may not be the best choice for drilling in hard-to-reach areas or extremely deep holes.
- Long: Offers the most flexibility and is ideal for drilling deep holes or in hard-to-reach places, but may be more prone to breaking or bending.
Flutes
Flutes are the grooves that run spirally along the length of a drill bit. They serve to remove chips and debris from the hole as the bit cuts into the material. They are also typically wider and deeper on larger diameter bits. Flute design can greatly affect the performance and efficiency of a drill bit.
Types of Flute Designs
- Standard flutes: Standard flutes are straight and are found on most drill bits. They are versatile and suitable for most materials and drilling applications, but may not be the most efficient option for harder materials.
- Parabolic flutes: Parabolic flutes have a deeper flute design and are more efficient at chip removal, making them suitable for softer materials, such as wood or plastic. They may not be as effective for harder materials or larger diameter bits.
- Helical flutes: Helical flutes twist along the length of the bit, creating a longer cutting edge and improving chip evacuation. They are suitable for harder materials, such as metal or concrete, that require extra cutting power. On the other hand, they may be more difficult to control and require more force to start drilling
- Double flutes: Double flutes have two sets of flutes that run parallel to each other, providing extra stability and control for drilling straight or accurate holes in wood or metal. They provide extra stability and control, but may produce more heat and friction during drilling.
Drill Bit Coatings
Drill bits have different coatings, each with its features, advantages, and disadvantages.
Black Oxide
Black oxide is a coating made by blackening the surface of the drill bit to enhance rust resistance and reduce friction. It is made from iron oxide and magnetite. They are best used for drilling soft metals such as aluminum, copper, brass, and mild steel.
- Advantages: Provides wear resistance and corrosion resistance. It also reduces friction, increasing the lifespan of the drill bit.
- Disadvantages: Not suitable for use on hard metals. It can also be easily scratched, which could affect the quality of the workpiece.
Bright
A bare metal finish with no coating. It is the most common type of drill bit. They are best used for drilling plastic, wood, and soft metals.
- Advantages: Easy to sharpen and provides good accuracy in drilling.
- Disadvantages: No rust resistance, and has a high friction level, causing heat buildup and reduced lifespan.
Titanium Nitride (TiN)
A gold-colored coating that provides heat resistance and hardness. It is made by depositing titanium nitride on the surface of the drill bit.
They are best used for drilling hard materials such as stainless steel, cast iron, and titanium.
- Advantages: Provides high heat resistance and hardness, which extends the lifespan of the drill bit. It also reduces friction and prevents galling and welding of the drill bit to the workpiece.
- Disadvantages: It is a relatively expensive coating.
Titanium Carbonitride (TiCN)
A gray-colored coating that is harder than TiN. It is made by depositing a layer of titanium carbonitride on the surface of the drill bit. They are best used for drilling abrasive materials like high-silicon aluminum, fiberglass, and carbon composites.
- Advantages: Provides a harder and more wear-resistant coating than TiN. It also has high lubricity, reducing the heat buildup and friction between the drill bit and workpiece.
- Disadvantages: It is more expensive than TiN.
Other Common Coatings Used in Drill Bits
- TiALN: A dark gray-colored coating that provides extreme hardness and heat resistance. It is best used for drilling hardened steels and stainless steel.
- Diamond-Like Carbon (DLC): A black-colored coating that provides superior hardness and wear resistance. It is best used for drilling non-ferrous metals and plastics.
- Zirconium Nitride (ZrN): A copper-colored coating that provides high wear resistance and low friction. It is best used for drilling aluminum and other non-ferrous metals.
Types of Drill Bits
When it comes to drilling, there are various types of drill bits designed for specific materials and applications. Here are some of the most common types:
- Twist Drill Bits: These are the most commonly used drill bits and are suitable for drilling holes in wood, plastic, and metal. They have a spiral shape that helps to remove the material being drilled and prevent the bit from getting stuck.
- Brad Point Bits: These bits are designed for drilling clean and accurate holes in wood. They have a sharp center point that helps to start the hole and two cutting edges that make clean cuts along the sides.
- Auger Bits: These bits are designed for drilling deep holes in wood. They have a long, spiral-shaped flute that removes chips from the hole as it is drilled.
- Spade Bits: These bits are designed for drilling large holes in wood. They have a flat, paddle-like shape with a pointed tip that helps to start the hole.
- Forstner Bits: These bits are designed for drilling flat-bottomed holes in wood. They have a flat, circular shape with a center point that helps to start the hole and cutting edges that create a smooth, flat bottom.
- Hole Saw Bits: These bits are designed for cutting large holes in wood, metal, and other materials. They have a circular shape with a saw-toothed edge that cuts through the material.
- Step Drill Bits: These bits are designed for drilling holes in metal and other hard materials. They have a stepped design that allows for drilling holes of different sizes with one bit.
- Masonry Bits: These bits are designed for drilling holes in concrete, brick, and other masonry materials. They have a carbide tip that can withstand the hardness of masonry materials.
- Glass and Tile Bits: These bits are designed for drilling holes in glass, tile, and other fragile materials. They have a carbide tip and a specialized design that reduces the risk of cracking or chipping the material.
- Countersink Bits: These bits are designed for drilling pilot holes and countersinks in wood and other soft materials. They have a tapered shape that creates a conical hole and a flat bottom for screws or other hardware.
- Drill Bit Sets: These sets include multiple types and sizes of drill bits for various applications. They are a great option for those who need a variety of drill bits for different materials and projects.
Each type of drill bit has its own unique features, suitable applications, advantages, and disadvantages. Choosing the right type of drill bit is essential for achieving accurate and efficient results in drilling.
Maintaining Drill Bits
If you want your drill bit to function optimally and improve its longevity, proper maintenance is a must.
Proper Storage
- Store drill bits in a dry and clean location
- Keep them in their original packaging or a designated storage container
- Use a rack or pegboard to organize and prevent damage
- Avoid exposure to extreme temperatures and humidity
- Label the storage container for easy identification
- Sharpening and maintenance techniques
Sharpening and Maintenance Techniques
- Use a file or grinder to sharpen dull drill bits
- Keep the bit cool while sharpening to prevent overheating and damage
- Remove any burrs or chips on the cutting edge
- Check the bit regularly for signs of wear or damage
- Use lubricant or cutting oil during drilling to reduce friction and heat buildup
- Avoid applying excessive pressure during drilling, which can cause wear and damage to the bit.
Common Mistakes to Avoid When Using Drill Bits
When it comes to using drill bits, mistakes are not uncommon. These are some of the most common mistakes that you should avoid to ensure safety:
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- Using the wrong drill bit: Choosing the wrong type or size of drill bit can damage the material being drilled, the drill bit itself, or even the drill. Always use the appropriate drill bit for the material and project being worked on.
- Applying too much pressure: Applying too much pressure on the drill can cause the bit to bend or break, damage the material being drilled, or cause injury to the user. Let the drill do the work and apply gentle and steady pressure to avoid damaging the bit or material.
- Overheating the bit: Overheating the bit can cause it to become dull and ineffective, or even melt and break. Use the proper speed setting for the drill, and apply lubrication or cooling agents to reduce friction and heat buildup.
- Neglecting to use safety gear: Failure to use proper safety gear such as safety goggles, gloves, and earplugs can lead to injury or long-term health problems. Always wear the appropriate safety gear when using a drill to protect yourself from flying debris, loud noises, and other hazards