What is worse than a dull drill bit? A bit that dulls halfway into a project, that’s what. Chances are that at this moment you probably do not have a spare bit or even worse, you will have to go out and get one. What if the hardware shop is already closed for the day? If you find yourself in this situation more often than you care to admit, it might be time to buy a drill bit sharpener.
You might be thinking that it is just not worth the hassle to sharpen your dull drill bits or that it will be time-consuming. Well think again, we have compiled a list of sharpeners that can sharpen at least ten dull bits in the time it will take you to find your car keys. This list of top ten sharpeners will ensure that you never have to replace your favorite drill bit again.
Dull drill bits are not only annoying; they are dangerous to work with too. We have compiled a list of top-notch sharpening devices that will keep your drill bits in pristine working condition.
View the Best Drill Bit Sharpener, Below.
- Drill Doctor DD750X
- DAREX Drill V390
- Drill Doctor DD350X
- Drill Doctor 500X
- Woodstock D4144
- STKUSA 32652
- Chicago Pneumatic 61778
- Multi-Sharp 2001
- O3 DFRT52787 Multi Purpose
- Drill Master 98061
1. Drill Doctor DD750X
Drill Doctor Drill Bit Sharpeners are well known for their long-lasting diamond wheels and powerful motor. Whether you are a professional tradesman or a weekend DIY warrior, you can’t go wrong with a Drill Doctor DD750X. This is a versatile sharpener that offers you adjustable relief and a wide range of angles at which you can sharpen your drill bits. All Drill Doctor Sharpeners are engineered and manufactured in the U.S which makes it readily available for professional tradesman and hobbyists alike.
One of its most prominent features is the split point function model which creates and restores perfectly self-centering split point drill bits. The ability to accept any kind of drill bit, including masonry drill bits, is what really makes this sharpener stand out from the rest.
This is a full sized drill bit sharpener, even though it only weighs 3 pounds. It measures 13.8 x 5.8 x 11.8 inches, which is pretty standard for a regular sized drill bit sharpener. You can place it on your workbench for easy access while working without losing too much of your work surface. The sharpener comes standard with its own carry case in which your tool can be stored safe and sound when not in use.
The DD750X sharpens drill bits from 3/32” to 3/4” and has an adjustable material take-off feature which lets you decide exactly how much of the material is removed during sharpening. This is good news for your drill bits since it extends their lifespan tremendously by only taking off what is necessary.
Because the point angles can be set anywhere from 115 to 140 degrees, you can use it to sharpen split point or parabolic twist drill bits as well as carbide and cobalt points. Virtually any type of drill bit can be sharpened with precision in less than a minute, which means you can spend more time working and less time fiddling with your bits.
Drill Doctor Sharpeners know how to take care of your drill bits. Engineered with a longer chuck jaw and specialized jaw guides, you can sharpen your bits in a safe and precise manner. The DD750X not only sharpens split point bits like a pro, it can also turn a standard bit into a perfectly split point bit in no time at all.
The “Push to Stop” function ensures that you do not over sharpen or accidentally damage split point bits. An already installed diamond sharpening wheel will give you a professionally sharpened drill bit every time and is quick and easy to replace.
Regardless of the load or speed, the integrated magnet motor provides consistent power and torque throughout the whole sharpening process.
This is an electric drill bit sharpener with a 6-foot power cord which is a great working length. The permanent magnet motor puts out 120 volts of consistent power regardless of the load or speed. On the one hand, having an electric sharpener means that you will save more money on batteries and you can use it whenever you need it. However, if you find yourself in a situation where there are no power outlets, you might not be able to use it.
When you purchase your Drill Doctor, you will be surprised to find that a 3/4" chuck, as well as 180 grit diamond sharpening wheel, has already been pre-installed. The whole package comes in a neat carrying case and all you have to do is read the manual which is also included in the package. The extra wheel hub wrench means that you don’t have to scramble around for any extra tools when it’s time to change or replace the diamond sharpening blade.Check Price on Amazon ➞
2. DAREX Drill V390
Darex offers your business the option to purchase some of the world’s best-selling sharpening tools at an affordable price. With more than 35 years of industrial sharpening experience under their belt, Darex strives to bring you cost-effective, high-quality tools to sharpen your drills in-house. This means quick and easy work production when you need it most.
This simple and affordable Precision sharpener is specifically designed for use in small shops and businesses. It can sharpen a whopping 35 to 50 drills per week and includes a split point feature which is great for relief control and a variety of point styles. The 3-step sharpening system will give you sharp drill bits in under a minute which is a huge time saver. The Darex V390 is perfect for DIY enthusiasts and small professional businesses alike.
The V390 is a manual bit sharpener with a cutting tool diameter of 1/8" – 3/4" and a morse tapered chuck. At 25Lbs, the Darex V390 comes in much heavier than the Drill Doctor DD750X but at more or less the same dimensions. The weight alone gives you the feel of a durable and solid piece of machinery which is why it is a favorite in the workplace.
The Darex V390 sharpens drill bits of 1/8in.-3/4in” and at an impressive 118 deg to 140 deg with ease. It comes standard with a Borazon wheel for high-speed steel and cobalt bits but does have an optional diamond wheel for carbide points which is sold separately. The Borazon wheel has a diameter of 3 inches and a grit of 180 which gives smooth and precise sharpening.
An optional grit vacuum can be added to minimize clean up time and keep the sharpener clean and free of debris. The morse taper mounting is a simple, low cost yet versatile mounting which allows for quick and easy sharpening and release of drill bits.
This compact, yet sturdy drill bit sharpener comes with a pre-installed Borazon Sharpening wheel. Borazon is one of the hardest known materials alongside various forms of diamond and boron nitride. The borazon crystals are formed by heating equal amount s of boron and nitrogen at a hellishly high temperature of 3300 Degrees Fahrenheit. The V390 has a good solid feel to it and is sturdy yet compact enough to save space on your workstation.
This is an electric corded drill with a varying output of voltage. The voltage ranges from 115V to 230V at 3450RPM. Since this tends to be a heavier drill sharpener, it can be placed in a designated area with a power outlet.
Reviews showed that customers who purchased the Darex V390 for their small shops and businesses viewed this as one of the best sharpeners on the market. Drill bits tend to become dull fast and can eat a large portion of your profits if you need to replace them regularly. This is a professional quality sharpener which delivers sharper bits with speed and precision.Check Price on Amazon ➞
3. Drill Doctor DD350X
The DD350X is a great option for your home workshop. It provides the homeowner, weekend craftsman, or hobbyist with the sharpening power needed to sharpen dull bits and finish projects without an extra trip to the hardware store.
This drill sharpener features a two-step system which eliminates the need for an alignment port. The DD350X simplifies the sharpening process, making it a hassle-free experience for DIY workshops at home. It doesn't get any easier than this, all you need to do is secure the bit and turn the chuck an even number of half turns to achieve a perfect 118-degree angle. A set of sturdy V-block jaws hold the bit precisely in place which minimizes jaw twisting, especially when working with small sized bits.
At only 3 pounds, this is drill bit sharpener is a very user-friendly size and will not take up too much space in your home workshop. Made from tool grade plastic and measuring 12.5 inches, this tool can be stored away neatly or placed in a permanent work area for quick access.
This drill sharpener is able to sharpen Carbide, Cobalt, Twist and Masonry bits without having to swap out the sharpening wheel. When the time comes to swop the diamond sharpening wheel, you can do so using the wheel hub wrench which comes standard with the DD350X. No extra tools are necessary which again, saves you time and money.
What makes the DD350X so versatile is that it can be used to sharpen all sorts of common bit styles ranging in size from 3/32” to 1/2" and is even works on wood and other light metals. Even though it is not able to sharpen or make split point bits like its big brother, the DD750X, it is still a very versatile sharpener for DIY Enthusiasts
As with any Drill Doctor Drill Bit Sharpeners, the DD350X is professionally designed and constructed for durability. Its cool design ensures that your bits don’t overheat or lose their tempering during the sharpening process. The industrial strength diamond sharpening wheel is designed to not change its shape over time
There is no need for an alignment port since the On-Chuck alignment simplifies the sharpening process on its own. The sturdy set of V-Block chuck jaws ensure that no bits can get stuck or twisted. Not even the smallest of bits will slip through these durable jaws.
This drill bit sharpener is an electric corded tool with a 6-foot power cord which is compatible with any standard 120-volt outlet. The permanent magnet motor produces consistent power, regardless of the load or speed.
Drill Doctor strives to give their clients value for money which is why each Drill sharpener comes standard with a size specific chuck and 180 grit diamond sharpening wheel, both of which are pre-installed. A detailed user guide is also included in the package as well as a wheel hub wrench which makes changing the sharpening wheel quick and hassle-free.Check Price on Amazon ➞
4. Drill Doctor 500X
The 500X is perfect for serious DIY hobbyists and professional users who need to sharpen bits frequently. The 500X is built tough and sharpens drill bits to 118 or 135-degree point angles. It is ideal for workshops that use separate bits for drilling wood and metal. Drill Doctor is part of Darex, a 4th-generation family-owned company in Ashland, Oregon. For over 40 years they have been creating industry-leading sharpening tools in the USA. They are over 100 co-workers strong, dedicated to producing high-quality tools and impeccable customer service.
The 500X sharpens Carbide, Cobalt and Masonry bits with ease thanks to the longer chuck jaws which are able to hold bits in a precise manner. This feature ensures that the jaw does not twist on smaller sized bits. This Drill Doctor model is able to create and sharpen split point bits which makes it a must-have for professionals and small shop owners. Having a sharpener that can create split points will save you a lot of time, money and effort.
At 4.2 pounds and 13.8 inches, this model is slightly heavier than both the DD350X and the DD750X although it is more or less the same size, give or take an inch.
This Drill Doctor model sharpens twist and masonry bits at an angle of 3/32 to 1/2 an inch which is pretty standard. For anything above 3/4”, there is an optional chuck accessory available separately. It can sharpen anywhere between 118 and 135 degrees which proves just how versatile this tool really is. It's worth mentioning again that it is not only able to sharpen split point bits but can create them too.
Because of its heavier weight, the 500X has a more solid feel to it. The point angle shuttle is made from cast aluminum which also attributes to this models durability. The diamond sharpening wheel is designed to keep its shape during its lifespan.
This is an electrically powered drill bit sharpener with a lengthy 6-foot power cord which can be plugged into a normal power outlet. The permanent magnet motor produces consistent power regardless of speed or load.
There are a few optional accessories available for this drill bit sharpener model and can be purchased separately. For reverse twist bits you can add a left-hand chuck or if you need to tackle ¾" Bits, you can grab a larger bit chuck. There is also a coarse 100 grit diamond sharpening wheel available as opposed to the standard 180 grit. By interchanging these components as needed, you will have drill bit sharpener that really can do it all.Check Price on Amazon ➞
5. Woodstock D4144
If you have a bench grinder with a side wheel this will help you get a lot more use from your drill bits. It is suitable for 1/8 to 3/4 inch bits and will do a good job with wood drill bits at a very modest price. The Woodstock D4144 is a popular model and has a very detailed manual which is available online. It is worth reading through to be sure that you will be comfortable and confident when using the device. Keep in mind that will you need to sacrifice some space to the side of your bench grinder to fix the jig in place.
The D4144 can easily be adjusted to accommodate various drill-point angles and can sharpen bits from 1/8 to 3/4 inches. This means that it is capable of sharpening a variety of bits with speed and accuracy.
This is a very light form of drill bit sharpener and weighs only 1.35 pounds which is great considering that it is usually attached to your bench grinder. The grinding wheel is 8 inches diameter and is about 1 1/2 inch thick, which brings the total dimensions to 7.9 x 5.2 x 1.8 inches. This is more or less the space it will take up alongside your bench grinder.
The "lockdown" feature of the bit is very reliable when using a side grinder at a low speed. This helps to keep the bits cooler and although it cannot cut split points or any other fancy cuts, it can accommodate bits ranging from 1/8 inches to 3/4inches and is adjustable for various drill-point angles.
This model is quite versatile because you can choose from a number of different grinding stones instead of the usual pre-installed stones. This gives you the freedom to experiment with different grits which are easily interchangeable.
Even though this drill bit sharpener is much smaller than most, it is durable and reliable while being able to fit in the palms of your hands. By removing the rear adjustment port, you will find it easier to maneuver the bit by applying some extra hand tension. It is strong enough to allow the user to sharpen the bits at a variety of drill point angles too.
The D4144 is a manual drill it sharpening attachment of sorts and is installed next to your bench grinder. Although it is not a very large attachment, you will still need to have an adequate amount of space available on your workbench. Since it is not corded, you can easily install this attachment wherever it is needed.
The great thing here is that that you have the liberty and options to choose from various grinding stones instead of settling with a manufacture-fixed one. This means that you can sharpen just about any size bit with the same drill bit sharpener.Check Price on Amazon ➞
6. STKUSA 32652
The STKUSA 32652 is a double-headed sharpening system that allows you to extend the life of all of your favorite and most useful bits. It will also keep your high-quality bits in pristine working condition.
This is an electric sharpener and so you don’t need to attach it to any drilling or grinding machines in order to use it. The feature that stands out the most on this drill bit sharpener is the fact that it has two sharpening heads. One head is able to sharpen smaller sized bits and the other works for larger bits. With the smaller head, you can sharpen bits from 1/8 to 3/8inches while the large head can accommodate bits from 5/16 to 5/8inches.
Even though this drill bit sharpener has two sharpening heads, it is still more or less lightweight and compact. At 4.42 pounds, you can feel just how durable and sturdy this tool is although it is made mainly of plastic.
This STKUSA model can sharpen both carbon steel and high-speed steel bits. It can be adjusted between twist bits and split point bits which makes it very versatile for its price range. Something that is not featured on many other drill bit sharpeners is the different speed settings available for each individual head as with the Neiko. The smaller head reaches and operates at 1400 rpm while the larger one runs on 1600 rpm
Thermal protection helps to prevent overheating and a set of sturdy rubber feet provides stability during the sharpening process. These rubber feet also grip your work surface to prevent the sharpener from sliding around. The sharpener is housed in high impact plastic which makes it durable enough to withstand any workshop environment.
As an electric drill bit sharpener, the STKUSA 32652 comes standard with a built-in internal AC adapter and a six-foot power cord which can be plugged straight into a power outlet.
The motor runs at two different speeds to accommodate two separate rpm; 1400rpm and 1600rpm.
With two heads instead of one, you can be sure that the STKUSA 32652 offers you great value for your money. With the ability to sharpen over 50 bits a month for use in the home workshop, this sharpener is also known to leave a very nice edge on high-quality bits.Check Price on Amazon ➞
7. Chicago Pneumatic 61778
The Multipurpose Sharpener from Chicago Electric Power Tools covers all of your professional and household sharpening needs in this convenient and compact (8”x6”x6”) machine. Keep your cutting and scraping tools razor sharp with this multi-task sharpener. This machine allows you to sharpen high-speed steel drill bits from 1/8" to 3/8", straight edge chisels and planer blades from 1/4" to 2" wide, as well as scissors and knives.
Featuring a well balanced 70-watt motor, this sharpener runs quietly and efficiently and is a great sharpening tool for any home garage or professional shop.
This is a multi-tasking multipurpose sharpener from Chicago Electric Power Tools. It is able to sharpen high-speed steel drill bits from 1/8" to 3/8" as well as straight edge chisels and planer blades from ¼” to 2” wide. Not only can it sharpen a wide variety of tools, but it can also be used to sharpen knives and scissors as well.
Measuring only 8 x 6 x 6 inches, it is very heavy for its small size. It weighs 4.15 pounds which is almost as heavy as the Neiko which boasts two heads. Unfortunately, the small size and heavyweight ratio seem to leave this tool slightly unbalanced and prone to vibrations. An integrated rubber base does help to absorb most of these vibrations and keep the tool only slightly more stable.
It is able to sharpen high-speed steel drill bits from 1/8" to 3/8" as well as straight edge chisels and planer blades from ¼” to 2” wide. This tool also sharpens knives and scissors. You can keep all of your cutting and scraping tools razor sharp with this multi-tool.
This is a very compact yet mildly heavy sharpening tool. With such small dimensions, the fast rotating speed can throw the tool off balance. A built-in rubber mat helps to absorb most of the vibrations and stops it from vibrating itself off of your work surface.
This tool is an electric tool and uses 120v, which is the same outlet as TV plugs into. The well balanced 70-watt motor ensures quiet and efficient operation and the 4800 RPM operation speed is supposed to provide total workpiece control.
This is a multi-tasking tool that is able to sharpen chisels, planer blades and high-speed drill bits. Scissors, knives or any other cutting or scraping tools can be sharpened on this compact sharpening tool.Check Price on Amazon ➞
8. Multi-Sharp 2001
The Multi-Sharp ATT2001 Dual Purpose Sharpener will accurately sharpen high-speed steel and masonry bits and Brad center point bits. This is a grinding jig tool which accurately positions each type of bit over the wheels (aluminum oxide and silicon carbide), and grinds the correct tip and relief angles. It can also be powered by an electric drill.
This lightweight yet sturdy grinding jig has all the angles for correct tip geometry built in. It positions each type of bit over the wheels to give the correct tip and relief angles. The unique cam action ensures correct tip rake and chisel edge which means it is more accurate than your average grinding jig.
This tool is a jig sharpener only and is used in conjunction with an electric drill. It is small and lightweight at only 11.4 ounces and can easily be held in on hand. Because the tool itself is so small, it is a bit of a hassle trying to sharpen smaller size bits.
This sharpener can be adjusted to any power drill to accurately grind and correct tip angles. It will also restore the cutting edges of high-speed steel, flat wood, and masonry bits. The grinding wheels are also interchangeable which allows you to pick and choose the grit you are most happy with.
This product is sent out in a strong plain box, which doubles as useful storage for the product parts. The sharpener fits any power drill and can accommodate a drill bit capacity of 3-13mm. The long life, high-quality Aluminum Oxide, and Silicon Carbide wheels sharpen at least 150 High-Speed Steel / Wood bits and 75 Masonry bits based on 6.5mm diameter. These grinding wheels are replaceable and interchangeable.
It can be startd and powered by an electric drill and does not need its own personal power source. It also re-edges and re-sharpens scribers, bradawls, punches, cold chisels and TCT tile and laminate cutters.
This sharpener can extend a drill bit life for years, and save you time and money. The high-quality aluminum oxide and silicon carbide wheels sharpen at least 150 High-Speed Steel/wood bits and 75 masonry bits. Replacement wheels are available and can be changed to suit your grinding preference.Check Price on Amazon ➞
9. O3 DFRT52787 Multi Purpose
This tool can be considered as the electric, Big Brother version of the Multi-Sharp 2001 and is the perfect addition to your home workshop. The multi-task sharpener allows you to sharpen high-speed steel drill bits from 1/8 in. to 3/8 in., straight edge chisels and planer blades from 1/4 in. to 2 in. wide as well as scissors and knives. Use it to keep your cutting and scraping tools razor sharp and in pristine working condition.
This is a Multi-Purpose Sharpener, Electric Powered, High-Speed Drill Bit Sharpener. It allows you to sharpen most high-speed steel bits from 1/8" to 3/8" and chisels and planer blades from ¼" to 2" wide. It can also sharpen scissors and knives with ease.
Take the drill diameter of 7/64”- 3/8”, and the wheel diameter of 2” and you will see that this is the perfect tool for sharpening knives and scissors as well as chisels and planes. With an 8” set of dimensions all around, this regular sized sharpener won't take up to much space on your workstation. The almost square dimensions make it easy to store.
This tool can be used to sharpen high-speed steel drill bits and straight edge chisels or planer blades for up to 2” wide. Apart from your run of the mill workshop tools, you can use this sharpener to sharpen knives and scissors too. That makes it a great all-round tool for the home and workshop alike.
Thanks to its compact size, this drill sharpener is quite stable and not prone to excess vibration. The gray and green composite plastic housing is designed to be rugged and durable. Rubberized feet ensure that the tool does not move around on your workbench during the sharpening process.
Apart from being affordable, durable and versatile, this multi-purpose tool is also electric. The 5.5-foot power cord is UL listed and can be plugged into any standard 120V power point. A well balanced 70-watt motor provides consistent 4800rpm and quiet operation during the sharpening process.
The list of scraping and cutting tools that this multi-purpose sharpener can sharpen is endless, which means you really get value for your money with this all in one tool. You would expect to pay an arm and a leg for something this versatile but it has made our list because of its affordable price tag.Check Price on Amazon ➞
10. Drill Master 98061
Save money and prolong the lifespan of your favorite drill bits by using this very affordable little drill bit sharpener. It easily attaches to any standard electric drill which means you can sharpen your bits quickly and easily.
Use this drill bit sharpener with your power drill to keep bits sharp and ready for use. The drill bit sharpener puts an edge on drill bits from 5/64 in. to 1/2 in.. The 100 grit stone gives a smooth, even edge to drill bits.
Weighing only 4 ounces, this is definitely one of the smallest sharpeners on our list. Big is not necessarily better, which is the case with this small tool. It can be kept in your pocket for easy access while working and is small enough to fit into the palm of your hand.
With a stop angle of 60 degrees to the left, this tool can accommodate a variety of drill sizes; 5/64" - 13/64"(2mm-5mm) 7/32" - 21/64"(5mm-8mm) + 11/32" -1/2"(8mm-12.5mm). This is quite versatile considering its small size. It is safe and easy to use with the appropriate built-in guides which keep your fingers away from the sharpening stone while in use.
Quite durable for its size, the metal shaft offers a degree of support to the plastic body. The 100 grit grinding stone is housed within the plastic body and gives a smooth even edge to drill bits. We do not recommend applying a lot of pressure while using this sharpening device due to its small size and plastic body.
This mini sharpener requires a Power Drill that operates between 2000 and 3500 RPM. It is not an electric tool and does not have a motor or power cord.
As far as price goes, you won’t find a cheaper tool to sharpen your bits with than this. It might not be as rugged or compact as the rest of the tools on our list but it can still sharpen with the best of them. As long as you don’t try to use it as an industrial sharpener, you should be fine.Check Price on Amazon ➞
Drill Bit Sharpener Buyer’s Guide
What to look for when Buying a Drill Bit Sharpener?
When looking for a drill bit sharpener, it makes sense to first look at the type of drill bits you want to sharpen. The most logical choice would be to choose one that can sharpen a wide variety of drill bits especially masonry and split point bits which are the most challenging bits to sharpen. A great drill bit sharpener should be able to restore perfectly centered split point bits quickly and accurately.
Drill bit sharpeners come in all shapes and sizes so how do you know which size to choose? The answer is simple really, the size of the sharpener will be relative to the space you have available on your workbench. An oversized and overweight sharpener is going to take up a lot of precious working space and will probably be heavy too, which means you are not going to feel like lugging it around all over the show.
We have already mentioned that you should consider the two most difficult types of drill bits but what about other tools? A versatile sharpener would be one that is able to sharpen and re-edge other tools such as chisels, knives and even scissors. This would give you the perfect all round sharpening tool.
This is probably the most overlooked aspect of any tool, its durability. Power tools have a tendency to vibrate, which means their components need to be rugged and durable or the whole tool could end up falling apart over a certain period of time. Cast aluminum is a very durable material as is silicon carbide, both of which would be big durability plus when buying a drill bit sharpener.
We all want value for our money and this means that we do not mind paying for something as long as it lives up to its promises. If it seems too good to be true it usually is. We recommend looking at drill bit sharpeners that offer you more than you bargained for and we don’t mean additional freebies. We mean feature-rich tools that are durable enough to last a lifetime. That is value for money
The power source is more of personal preference and everyone’s opinions will differ as to which is better; electric or manual. Most electric sharpeners can be plugged into your average 120 v power source which means you can plug it in and use it immediately. If you find that you will be working where there is no power then a manual one is a good idea. Some sharpeners can be placed next to your bench grinder or be attached to an electric drill.
Before you run out and purchase a drill bit sharpener, think about what you are going to be using it for. Small workshop owners will go through a lot more drill bits than the average DIY hobbyist. Of course, there is nothing stopping you from having an industrial sharpener at home but you might want to rethink trying to use a mini multi-tool in an industrial set up.
Some sharpeners take patience and practice while others can practically run themselves. For a small workshop, we recommend looking for a sharpener that is fast, durable and compact. You do not want your tradesmen spending all of their time in front of the sharpeners and none on the actual workload.
There are drill bit sharpeners with great features such as being able to create split point drill bits or re-edging scraping tools. These features all seem great but your main concern should be precision. So many sharpeners claim to be fast and accurate but not many are and that is the main reason for this list of top drill bit sharpeners.
Nifty Drill Bit Sharpening Trick: Use two hex headed bolts and nuts and mount them in a piece of off-cut steel or timber so that two of their edges are touching (as shown). After sharpening your drill bit carefully on a bench grinder, remove the bit and test against the two hex head bolts as shown in the image. You also need to ensure that the bit being sharpened remains perpendicular to the shanks of the bolts to make sure the cutting edges of the bit are properly angled.
Did you know?
If you find yourself in need of sharpening a utility knife, pocket blade, or scissors and don’t have access to a sharpening stone, you can flip over a ceramic coffee mug and use the outer edge of the bottom (the non-glazed part) as an emergency sharpening stone.