Buying guide for best countersink drill bit sets
As anyone who has built furniture or cabinets can tell you, accuracy and attention to detail are two big factors that distinguish unremarkable work from expert craftsmanship. However, putting that coveted professional touch on your projects requires more than perfectly planed surfaces and tastefully selected stains and finishes. Keeping screws flush to the surface of your project while still maintaining a tight and long-lasting grip requires a set of high-quality, durable countersink drill bits.
Countersink drill bits are simple tools, but there are still a number of considerations when shopping for them. Keep in mind the size of holes you intend to make and how many bits you need in a set. Accessories like a storage case and woodworking tools add value to the purchase, especially if you’re just starting out.
Look for bits made of high-quality metal, and consider the materials that you plan to use them on. Some bits are designed for softer materials like wood and drywall, while others are durable enough to cut into aluminum and steel. All-in-one options with removable drill bits clamped into a countersink sleeve are the most efficient; they allow you to carve out the pilot hole and countersink in one fell swoop.
We have determined the DeWalt Countersink Drill Bit Set to be the best all-purpose kit for both professional and DIY projects. Thanks to the company’s outstanding reputation for well-made tools, and hex screws that offer unparalleled tightness, we’re confident that these countersink drill bits will keep turning out great-looking projects for years to come.
Best countersink drill bit sets
This all-in-one set from DeWalt includes #6, #8 and #10 countersinks, each with an accompanying tapered drill bit. The attached bit pieces allow you to drill an expertly finished hole in one motion without having to swap tools or accessories. With the included 1/4-inch hex wrench, the drill bits can be adjusted, removed and replaced if they wear out, greatly extending this set’s usable life.
Unlike offerings from competitors, each piece includes not one but two set screws. This design makes it easy to center the bits in the countersink and greatly reduces the chances of them loosening as you work. Pros and amateurs alike will reach for these bits time and again.
Don’t let the price of this budget-friendly, seven-piece countersink drill bit set fool you. These high-quality carbon steel bits have a three-pointed design that bites into material for quick, accurate holes and an expert finish. The all-in-one set includes a padded case for keeping tools safe and organized, as well as the hex wrench needed to remove, exchange or tighten the drill bits.
An additional hex screw in the countersink would better secure the drill bits and lessen concern about loosening. However, this set is still a good buy for anyone looking to add versatility to their carpentry toolkit without spending a lot.
Each of the 1/4-, 3/8-, 1/2-, 5/8- and 3/4-inch countersink bits included in this set feature five flutes that apply maximum cutting power to your project. This design reduces any vibrations that could result in slipping, hand fatigue or rough edges. Made of high-grade steel, these bits are built to last. They come in a latching metal storage case with thick foam padding.
While these bits aren’t as sharp as some users would prefer, they’re perfect for wood and soft metals like aluminum. With this reasonably priced set, you should find the size bit needed for almost any application.
The industrial-grade steel 1/4-, 3/8 -, 1/2 -, 5/8- and 3/4-inch bits in this set kit have an 82-degree tip that makes them ideal for countersinking into soft metals. The five-fluted design keeps the drilling smooth and precise, and the black oxide finish resists corrosion caused by sweat or humidity. The bits fit snugly into an included storage case with clearly labeled dividers and a transparent window for visibility.
The barrels on these bits lack flat edges, making them easy to line up in both hand drills and presses. However, this design may result in some slipping if you use a tool that lacks a quality chuck.
This kit includes six high-speed steel countersink drill bits featuring a 90-degree cutting tip for deep screw setting. Three flutes give these bits the edge needed to put the finishing touch on projects from drywall installation to cabinetry. These countersinkers work great on wood, but they’re also designed to bite into metals like aluminum and steel.
These bits tend to result in some chatter when used in a hand drill, so for the most accurate results, we recommend using these bits in a drill press. Available in metric sizes only, each set includes 20.5-, 16.5-, 12.4-, 10.4-, 8.3- and 6.3-millimeter bits.
This set of five countersink drill bits packs in the value, allowing you to expand finishing abilities for a price that’s hard to beat. The FTG USA set includes both countersinks and drill bits for speedy work. The bits are made of a harder high-speed steel than most competitors’ offerings. The drill bits shoot through material with little effort and their tapered shape ensures that screws maintain a good bite along their entire length.
While durable and well made, these #4, #6, #8, #10 and #12 bits are best used on wood and other soft materials. Unfortunately, this kit does not include a storage case.
This kit includes three chamfering bits, seven countersink drill bits, a hex wrench and a compact plastic storage case. Each piece of hardware is made of industrial-grade carbon steel, which means they’ll maintain sharpness through long periods of heavy use. The bits have a smooth shank for hassle-free insertion into a press; the chamfering bits have flattened edges to ensure a secure, slip-free grip.
Five cutting blades keep chatter to a minimum and result in smooth, refined edges for superior workmanship. With a 90-degree cutting angle, these bits allow for deep countersinking in wood and similarly soft materials. Countersink sizes are 1/2- and 5/8-inch, depending on drill bit size, and the included chamfering bits are 1/2-, 5/8- and 3/4-inch in diameter.
With 26 pieces included, this starter woodworking set is great for anyone looking to take their carpentry skills to the next level. In addition to seven countersink drill bits (3, 4, 5, 6, 7, 8 and 10 millimeters) and six chamfering bits, you get three step drill bits, four plug cutters, a hex wrench for adjusting your bits and an automatic center punch. The tools are made out of high-quality steel for cutting into wood, plastic and aluminum.
A case is included with this set. However, because it doesn’t have specific slots for the included pieces, the case isn’t the best way to organize and protect them.
Machined from high-speed steel, these countersinkers have a 90-degree cutting angle and five flutes for chatter-free drilling and smooth operation. Hexagonal shanks let you tighten these bits securely to make precise holes whether you’re using a hand drill or a stationary press. With 1/4-, 5/16-, 3/8-, 1/2-, 5/8- and 3/4-inch bits included in the kit, you can grab everything required for the vast majority of countersinking jobs in one purchase.
These budget-friendly bits aren’t as sharp as some may expect, so we recommend using them at a slow speed and only on wood, particle board, drywall, plastic and soft aluminum.
What to know before buying a countersink drill bit set
Materials
High-speed steel: The cheapest countersink drill bit sets contain bits made of standard high-speed steel (HSS). It's a proven material used for all kinds of cutting tools and forms the base for all types of countersink drill bits. HSS is excellent at cutting wood as well as most plastics and composites. The material can also cope with aluminum and other soft metals, but it struggles with steel and cast iron because it tends to overheat and dull quickly.
Heat-treated HSS: Standard HSS can be improved by heat treating, which gives it a black oxide coating. These bits are less prone to rust and create less friction, which means greater efficiency.
M2: This is high-speed steel with tungsten and molybdenum added, which makes for a much harder material that’s better suited to drilling metal.
Cobalt: Another improvement on HSS is made by adding cobalt. This creates the hardest and strongest of all drill bit types. You'll find them in many professional machine shops, but they’re expensive.
TiN: Countersinks described as TiN use a titanium nitride coating (a type of ceramic). They are usually gold-colored. These are efficient at cutting because they’re very hard, low friction and good at dissipating heat. The drawback with TiN is that it's a coating rather than part of the metal. When the drill bit wears out, it can't be resharpened or recoated; it has to be thrown away.
Countersink drill bit types
Standard: These bits have a cone-shaped tip and cutting flutes that extend down the sides. They are designed to countersink an existing drill hole. Variations on this type are available for drilling all materials.
All-in-one: These bits have a hole in the middle that accepts a smaller diameter (pilot) drill bit and often a depth stop. They’re capable of drilling the initial hole and then countersinking or counterboring it. Because the pilot drill is usually HSS or black oxide, these are generally only used for drilling wood and other softer materials, not steel or cast iron. If the pilot drill bit has a point and spur on the end, it's designed for woodworking only.
Tapered: Some pilot drill bits are tapered, which is claimed to make for faster, smoother drilling. It also provides a larger grip area for a tapered screw — which gives stronger fixing — as long as you accurately match diameter and depth to the size of screw you’re using.
Cross-hole: These countersinks don't have flutes but a single hole drilled through the head at a 45-degree angle. Although called a “countersink,” these are actually used for deburring existing holes, usually in various types of sheet metal.
Flutes and shanks
Flutes: The drill bits usually have three or five flutes. A countersink drill bit with three flutes cuts more aggressively. If the bit has five, it cuts with less vibration and enables a smoother finish.
Shanks: These are round or hexagonal. Round shanks are common on countersinks used for hard metals because they're designed to fit machine chucks (though they fit other types too). Hexagonal shanks fit all kinds of drills and may also be of the quick-release type.
Additional features
Sets contain between three and seven countersinks, giving you an enormous range to choose from.
All-in-one sets: These should also contain a hex key, which is used to adjust depth stops or replace worn pilot drills (the countersink part tends to last much longer). Sometimes two hex keys are provided, which is great because it’s easy to lose one.
Woodworking sets: These might also contain one or more plug cutters and perhaps a quick-release chuck adapter.
Storage: It's nice to have a box to store the set in. It's not just a neat and convenient way to keep the drill bits, but if they’re banging against other things in your toolbox, the cutting edges could be damaged.
Tips for using countersink drill bits
- Check the chamfer angle of the screw heads. Most are 82 degrees, but metric screws are often 90 degrees, and other angles exist. If your countersink angle doesn’t match, the screw won’t sit properly. If the screws are hidden, much of the time it won’t matter. But if they’re visible, it looks wrong. In hardwoods, it can even weaken the screw head and in extreme cases cause it to break.
- Mark the position with a center punch first when drilling in metal. Solid models are tapped gently with a hammer; spring-loaded models are simply pressed until they activate.
- Work out the required depth carefully when doing counterbores. Too shallow and the screw won’t grip properly; too deep and there’s a danger of it pulling through.
- Deburr the holes. A countersink isn’t just for making recesses. It’s also the fastest way to deburr a hole in sheet metal or pipework. A quick twist of the hand is often all that’s needed.
FAQ
Q. How much does a countersink drill bit set cost?
A. The cheapest countersink drill bit sets cost less than $10, but they usually blunt quickly, which leads to rough edges. In our opinion, there seems little point in trying to save a couple of dollars when you can get a quality set for a little more.
Good, basic woodworking countersink drill bit sets cost $15 to $20, and equivalent metalworking sets cost $30 to $40. The main difference between countersink-only sets and those that offer pilot drill, countersink and counterbore isn’t usually the price but the number of drill bits provided. You’ll usually get five or six countersinks but only two or three combination bits.
Precision cobalt countersink drill bit sets can cost over $100 and as much as $200. However, these are premium-quality professional tools, so one of these sets is worth the investment if your work demands it.
Q. What’s the difference between a countersink and a counterbore?
A. A countersink is a shallow conical depression — deep enough so that when the screw is inserted, the head is flush or slightly below the surface of the material.
A counterbore is a smooth-sided hole the same diameter or larger than the screw head with a countersink at the bottom. A counterbore allows a screw to be used in material that might otherwise be too thick. In woodworking, it can also be used to hide the screw head, either with filler or a wood plug cut to the same size as the counterbore and glued in place. Once sanded down and varnished or painted, the hole is just about invisible.
Q. How can I avoid countersink chatter?
A. Chatter causes a rough rather than smooth edge to the hole — in severe cases almost hexagonal. A blunt countersink drill can cause it, as can the wrong drilling speed. However, the most common cause is bad alignment: the countersink drill isn’t following the same center as the initial pilot hole. It usually happens when you’re drilling by hand, so when possible use an all-in-one drill and countersink. If that’s not practical, try using a drill press.
Make sure the material is clamped or held in a drill vise so it can’t move. Drill the hole and follow immediately with the countersink. Another option is to drill the countersink first, then drill the main hole through the middle of the depression. It works, but the positioning of the countersink can be challenging. Without a pilot hole, they have a tendency to wander.
Q. Some countersink drill bit sets have numbers like #8 or #10. What do they mean?
A. These are gauge sizes, a system used to identify standard wire thicknesses that was first used in the U.K. in the 19th century. Britain now uses metric sizes, but numbers are still widely used in other countries. Most manufacturers also put the inch equivalent on the pack, though the sizes might not be what you expect.
The #8 countersink is 11/64 inch, close to 1/4 inch but not quite. For woodworking, the difference isn’t usually enough to be important, but for absolute precision in engineering, you need to be careful.
