How to sharpen an auger bit?

4th August 2021


	How to sharpen an auger bit


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			For this task, you will need an auger bit file at the ready! This is a type of file that has been specially designed to reach in to sharpen the cutting edges of an auger bit without causing damage to the flighting or guide screw. They are sold individually, and in one size only,For more information on these tools, see: Files

			The areas that you are looking to sharpen are the two spurs and the lips. (There may be two of these, or just one.)

			Sharpening lips and spurs
			Step 1 – Sharpen lips Sharpen the lips on your tool by giving them several strokes with your auger bit file. The lips are located near to the guide screw, at the bottom of each of the spiral flightings (there may only be one if you have a single-twist auger). To make sure you are following the right cutting angle, line your auger bit file up with the slope of the blade. It’s important that you don’t change it!

			Step 2 – Sharpen insides of spurs Using the same technique, file inside the spurs, matching the angle of the file to the inside surface of the spurs so as not to change the geometry of the tool.

			It’s important that you don’t file outside the spurs, as doing so will wear away material on the edge of the bit and reduce the size of hole that it will drill.

			Step 3 – Test it out Your auger bit should now be sharp. You can test it if it is by drilling a hole in some scrap wood. If it’s still struggling to bore a hole, repeat this process from step one.

			Sharpening the guide screw
			When sharpening a guide screw, the best results can be achieved using grinding paste, a compound containing abrasive particles that are designed to wear down imperfections in metal surfaces that are difficult to reach.

			Step 1 – Create reservoir Using the screw of the bit you would like to sharpen, bore just far enough into a piece of softwood for the guide screw to fully enter the wood, then remove the bit.

			Step 2 – Apply grinding paste Apply some fine grain grinding paste into the screw hole with the implement of your choice (you might use a toothbrush, a scoop or even a lollipop stick).

			Step 3 – Grind screw sharp Reinsert the guide screw into the bore hole and twist it backwards and forwards. This will cause the abrasive particles in the grinding paste to remove any dirt and sharpen the edges of the thread.

			Step 4 – Clean off excess paste Remove the bit from the bore hole and clean off any paste left on the screw. Check the packaging for the grinding compound to see if it’s water soluble. If it is, you can rinse it with water.

			If not, you will need to spray water displacing oil onto the guide screw before wiping it with a cloth.