Easy Method to Sharpen Drill Bits With a File by Yourself!

Published on: February 26, 2022
Written by Eric Devin / Fact-checked by David Rowan

We all have drill machines and also use different kinds of drill bits. But what do you do with worn out, dull, and burred drill bits? Professionals usually throw away and buy a new set. Who owns an angle grinder or bench grinder use those to sharpen the bits. 

Well, most DIYers and beginners or homeowners keep using the dull bits, not realizing the damage it is doing.  But it only takes few minutes to sharpen the drill bits with a tool that everyone keeps in their home. Yes, you heard it right. 

Drill bits are cutting tools just like knives and blades. And these can be resharpened like any cutting tools. The method is also the same, using a file. Just the procedure is a little different as the drill bit’s cutting edge is not straight like a knife. So, here we are to tell you about how to sharpen drill bits using only a file. 

Why Do Dull Drill Bits Need Sharpening? 

If I would ask why knives need sharpening, then it would be an absurd question. But people really don’t care about drill bits as they do about other cutting tools. These are cheap tool attachments and the problems using a dull bit is not well acknowledged. That is why a lot of users are not bothered using a dull bit. 

• A dull bit creates more friction with the material. It rotates more but cuts less. So, while it has longer contact with the material, it gets heated up. If you are using a drill bit on wood, there are possibilities that it will create smoke and lead to a fire hazard. 
• Another problem is, it makes the holes less clean. The opening of the hole may have edges that are not well-formed. This is a big issue when you need to make your work look perfect. 
• Sometimes, a slightly dull bit gets worn out quicker than the new one. If you resharpen it when the bit is still usable, then it will have a longer life and save you from spending on another bit set. 
• When we spend on new bits, we expect those to be perfect and razor-sharp. But the truth is, sometimes new, an unused bit can be dull. Hence, new drill bits may need resharpening if it is not as good as it should be. 

How to File-Sharpen Drill Bits

By using the proper files you can sharpen any bit you have. Whether it is spade bits or brad point bits, you just need to spend on a specific file once then you can keep your bits sharp whenever needed. 

Clean the Bit

At first, you need to clean all the dirt and debris the bit has on it. Use a dry cloth to clean the dirt. If the dirt seems stubborn, you can use a damp cloth and rub the drill bit clean. 

Clamp-on Table

Now use a table vise to clamp the drill bit to the table surface. I know everyone doesn’t have an accessory to clamp the drill bit on any surface. In that case, you can hold the bit on one hand and use another to sharpen it. This will be a bit awkward, but it is possible to sharpen the bit this way. 

Use Appropriate File and Wear Safety Glasses

Now, you need to use a diamond flat file to sharpen the bits. Most drill bits are made with high carbon steel. So, using a regular file won’t work on those as the bits are as hard as the files. So, you need to use a diamond file. Usually, a flat-file works on most hole boring drill bits. 

If you need to sharpen a spade file, use a mill file to sharpen it. For sharpening a brad point drill bit, use an auger file. Likewise, to sharpen a pilot point drill bit, using a needle diamond file is the most effective way. 

Wear safety glasses to protect your eyes. Do not use gloves as the burrs and knicks on the bits will attach to the glove material. 

Follow the Procedure

Keep the drill bit on the table and inspect its damage carefully. The lip of the drill bit is the main cutting tool. You need to reshape it to resharpen. But you can not damage the chisel angle in the process as the chisel supports the lip. 

• All you need to do is hold the file at 60 degrees and run it on the chisel 6 to 7 times on both sides. Remember, you have to create symmetry while sharpening the bits. An asymmetrical drill bit will make holes that are not entirely straight. 
• However, once you are done doing the chisel, now it is time to make the curve on the chisel. Just run the file left to the right with slight pressure. It will create the curved surface a drill bit always has. 
• If the drill has burrs on the sides, file down those too.

Test Manually

When you think the drill bit is sharp enough, you should test it manually. This way you can determine if the sharpening is okay or it needs more filing. Take the bit and spin it on a piece of scrap wood. It can mark on the wood easily, then it is done sharpening. 

Test with a Drill

Now it is time to finally use the bit with an actual drilling machine. Make holes on scrap material with it and look at the before and after results of the sharpening. If it is satisfactory, then your drill bit is alright. If not, then follow the filing procedure a couple of times more. 

Apply Oil

Some clean off the dust with water after sharpening the drill bits. But I recommend using machine oil. Just rub some oil on the drill bit and clean off the dust. I also recommend using 

A little amount of cutting paste before using any drill bit. It causes less friction and makes the drill bit last longer. 

People Also Ask

Is It Worth Sharpening Drill Bits?

To be honest, if you think of using power tools like an angle grinder, bench grinder, or sander just to sharpen dull drill bits, then no, it doesn’t worth it. Those tools are way too pricey than drill bits which are less than a dollar. 

But have you considered the risk associated with using worn drill bits? The risk and the amount of money to replace old drill bits with new ones may be worth resharpening the bits, but with a manual tool. These tools are cheap and available at home. So, yes drill bits are worth resharpening as long as the sharpening tools are cheap. 

Can I Use a Bench Grinder to Sharpen Drill Bits at Home?

Yes, you can use a bench grinder to sharpen drill bits at home. It is a popular sharpen drill bit technique. Make sure to carefully position the drill bit against the grinder wheel and maintain a steady hand for even sharpening. Remember to frequently check the bit for overheating.

What Is the Best Way to Sharpen Dull Drill Bits?

The best way of resharpening drill bits is with an angle grinder or bench grinder. Hand filing also works well, but the strokes you make may not always be the same all the time. A grinder just stays in place and the bit is held against it for a few seconds. So, the sharpening is uniform compared to hand filing. 

But using a hand file to sharpen drill bits has its own advantage. There is less chance of over sharpening. Once you master the skill, you will be comfortable using it and prefer filing the bits instead of grinding. 

Conclusion

Drill bits are cheap, but dull drill bits are evil enough to make you spend more due to their disadvantages. So, keep your tools sharp and in shape before using them. Replacing drill bits works for those who make a living with it, but it is not an option for people who rarely use and buy drills. 

So, filing the bits is an effective, cheap, and easier way to ensure that your drilling operations are done safely. All you need is to invest in the files once instead of the drill bits frequently.