How to Sharpen an Auger Bit — A Step-by-Step Guide

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Sharpening an auger bit can be daunting, especially if you’re new to the process. With so many techniques, tools, and materials involved, it’s easy to become overwhelmed and make costly mistakes.

However, neglecting to sharpen your auger bit can result in jagged holes, damaged materials, and injuries. So, in this step-by-step guide, we’ll show you exactly how to sharpen an auger bit.

Restoring Your Auger Drill Bits: Is it advisable to Sharpen It?

Yes, it’s advisable to sharpen auger drill bits, especially when they become dull or blunt. Auger drill bits are used to bore holes in wood; over time, they can become dull due to regular use.

Dull bits can lead to inefficient drilling, slower progress, and in some cases, can damage the wood being drilled. When you sharpen auger bits, you can improve their drilling performance and extend their lifespan.

What are Auger Bit Files?

Auger bit files are specialized files designed for sharpening and maintaining the cutting edges of auger drill bits. These files are typically tapered and have a triangular cross-section, which allows them to fit into the flutes of the auger bit.

sharpening auger bit

It has single-cut teeth located at both ends. One end has teeth on the wide faces while the edges are smooth, while the other end has teeth on the edges and wide faces without teeth.

This design enables you to work with precision on a specific part without the danger of unintentionally filing nearby surfaces.

The purpose of the auger bit file is to remove any unwanted sharp edges, burrs, or nicks that may have formed on the cutting edges of the bit and to restore the original shape of the bit’s cutting surfaces.

Auger bit file is available in various file sizes to match the different sizes of auger bits, and a file is often sold in sets that include several different sizes. When using an auger bit file, it’s important to be careful and take proper safety precautions, such as gloves and eye protection.

How To Use Auger Bit Files

So, how to sharpen an auger bit using an auger bit file? First, you must secure the auger drill bit in a clamp or a vise to prevent it from moving while you work on it. Next, position the auger bit file at the base of one of the cutting edges, holding it with both hands.

sharpening auger bit using auger bit file

Push the file towards the tip of the bit, following the angle of the main cutting edge. Use firm, even strokes and apply downward pressure evenly across the cutting edge. Once you’ve finished filing one cutting edge, move on to the next edge and repeat the process.

After filing all the cutting edges, use them to bore holes in the wood to check and fix if they are sharp and free of burr. If any burr remains in the tip of the main cutter, use fine-grit sandpaper or a honing stone to remove them.

Finally, use a cloth or a brush to clean a burr or any metal shavings or debris from the edge of the bit.

Sharpening An Auger Drill Bit Using an Auger Bit File

Necessary Tools & Materials

Process #1: Sharpening the Auger Bit Tips And Spurs

Step #1: Sharpening The Bit Tips

To sharpen an auger bit tips, which can be found at the lower part of each spiral round near the guiding screw, use an auger bit sharpening file and gently stroke the tips until they are adequately honed.

sharpening the auger tip

Maintaining the proper angle and precise control while cutting the tips and sticking to this angle throughout the sharpening process is important. This is crucial for effectively sharpening the spurs of the auger bit and making the cutting process smoother and easier.

To sharpen an auger bit effectively and ensure the best results, remember to mark the angle initially and not change it later.

Step #2: Sharpening the Insides Of the Spurs

Moving on to the second step, we will now focus on honing the inner edge of the spurs.
To ensure appropriate sharpening, it is crucial to maintain both spurs at the same height.

Start by using the same technique as earlier to sharpen insides of spurs, ensuring that the file angle matches the spurs’ inner surface.

This is important to avoid altering the geometry of the tool while stroking. Refraining from filing spurs outside’s surface is crucial as it can lead to the wearing away of material on the bit’s narrow edges, ultimately decreasing the hole size that the auger bit will drill.

sharpening the auger tip

Step #3: Do a Sharpness Test

At this point, your auger-cutting lips and spurs should be extremely sharp, like a blade. Verify or test now the sharpness of the drill bit.

You can do this by drilling a hole in a wood or a block. If you still encounter issues or it’s not still sharp while making a precise hole, use an auger bit sharpening file, then repeat step 1.

Process #2: Sharpening The Guide Screw

Step #1: Make A Reservoir

With the auger bit tips and spurs sharpened, you can now sharpen the guide screws.
The first step is establishing a reservoir by boring a hole in the softwood sheet. Ensure that the guide screw is fully inserted into the sheet of wood.

Once the bit file is removed, secure the bore hole, as needed, in the following step.

Step #2: Apply a Grinding Paste

The second step is to apply grinding paste on the guide screw and the bore hole created in the first step.

auger bit and file

To apply grinding paste with abrasive particles, you can use a toothbrush or a stick. Once the fine grinding paste has been applied to the screw hole, the next step is to sharpen the screw’s thread. This is achieved by running the drill in the same hole containing the paste.

The drill should be turned backward and forward to remove accumulated dirt on the screw and sharpen its edges. This step is crucial in ensuring that the guide screw is in good condition and can perform its intended function effectively.

Step #3: Sharpen The Edges of the Screw

Step three involves removing the drill bit from the hole and removing any excess grinding paste on the screw. If the grinding paste is water-soluble, we suggest washing the screw with water and then drying it with a fresh microfiber cloth.

These steps will result in a well-sharpened auger drill bit ready for use. It is important to note that besides using a metal file with teeth located on one side, other tools that can be used to sharpen drill bits, such as a drill bit sharpener, belt sander, or bench grinder.

Step #4: Wipe Off The Remaining Paste

After drilling the hole, the final step involves taking the bit out and wiping off any surplus paste on the screw. To ascertain if the grinding compound is water-based or not, refer to the information provided on its packaging.

touching the auger bit tip

If it is, then it can simply be rinsed off with water. However, if the grinding compound is not water-soluble, it will be necessary to use water-displacing oil to clean it off the screw.

The oil should be sprayed onto the guide screw and then wiped off with a cloth to remove any remaining paste or dirt. This step is crucial in ensuring the screw is free from any excess paste that could affect its performance.

How to Sharpen Your Lead Screw On An Auger Bit?

The initial stage of sharpening the lead screw on an auger bit involves the application of grinding paste with abrasive particles onto the lead screw of the main cutter. Then, the auger bit should be inserted into a hole in the softwood and twisted back and forth.

As a result of this process, friction is generated between the wood and metal surfaces within the hole, eliminating any flaws, debris, and grime present on the lead screw and, consequently, making it sharp.

You must be careful and exercise caution while sharpening tools since they may become extremely sharp. When sharpening, it is essential to always position the blade and wear away from yourself.

auger bit

After the sharpening job, it is important to wipe off any excess paste. Remove by rinsing the surface of the auger bit with water or by using WD-40. This will avoid affecting the performance of your auger bit.

Make sure to follow these simple steps to sharpen an auger bit lead screw for a smooth sharpening process, and the bit will be in good condition and ready to perform its intended function effectively.

What To Do If You Don’t Have An Auger Bit File: Are All Auger Bits Similar?

There is a simple solution if you find yourself without an Auger bit file and don’t want to purchase one. You can create your own file using a popsicle stick and some sandpaper.

Glue the sandpaper [1] to the stick, using a coarser grit for initial sharpening and a finer grit for honing. However, if you are a professional woodworker, investing in an auger bit file is advisable, as this tool is specifically designed to sharpen auger bits and yield optimal results in a boring hole.

It’s important to note that not all auger bits are the same, and different types of auger bits may require different sharpening methods.

types of auger bits

For example, some auger bits may have a different angle or shape to their cutting lips or edge, which could require a specific type of sharpening material or technique.

Some popular examples of auger bits include the triple-fluted auger bit, the earth auger bit, the ice auger bit, the carbide-tipped auger bit, and the wood boring auger bit.

Despite featuring a flue, tang, shank, twist, cutting lips, and screw, each type of auger bit has its unique edge, function, and design.

What are the Two Areas Sharpened on Auger Bits?

Auger bits require sharpening in two key areas: the inner cutting lips and the inside spurs. These areas should be sharpened correctly using a specialized auger bit file, ensuring that the sharpening angle is consistent throughout the entire sharpening process.

While sharpening the inner cutting lips and spurs of the auger bit, it is crucial to preserve the curved shape of the tool. It is necessary to avoid flattening or changing the shape of the bit as it can negatively affect its performance.

Therefore, the rounded geometry of the auger bit should be maintained during the sharpening process to ensure that it functions efficiently.

sharpening auger bit


Can you sharpen auger blades with a knife sharpener?

You can sharpen your auger blades with a knife sharpener, but it is not recommended as it may not be effective or safe. Auger blades have a unique shape and design that requires an auger bit file or specialized sharpening material to maintain their cutting properly.

More sharpening tips here


If you know how to sharpen an auger bit, you’ll surely extend the life of your tools, enhance their efficiency, and improve the overall quality of your work.

With correct sharpening techniques, you can keep your auger bits in peak condition, allowing you to easily and confidently tackle a wide range of woodworking projects.

Robert Johnson is a woodworker who takes joy in sharing his passion for creating to the rest of the world. His brainchild, Sawinery, allowed him to do so as well as connect with other craftsmen. He has since built an enviable workshop for himself and an equally impressive online accomplishment: an extensive resource site serving old timers and novices alike.
Robert Johnson
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