Drawing a Burr
When you’re first sharpening a blade, successfully drawing a burr from each side of the knife is the most important step. It is very difficult to know for certain without the presence of a burr if the bevels on each side of the blade actually extend to the edge. If the bevels do not extend all the way to the edge, the edge of the knife will be blunt and the knife will not be sharp.
A burr is defined as (From Wikipedia) ‘In engineering, a burr refers to the raised edge on a metal part. It may be present in the form of a fine wire on the edge of a freshly sharpened tool or as a raised portion on a surface, after being struck a blow from an equally hard, or heavy object.’ A burr, also called a wire edge, is created as a result of sharpening metal. The burr forms on the edge of the knife where the planes of the bevels (or, in the case of one-sided knives or chisels, the plane of one face and the bevel) intersect. The diagram below shows the burr projecting from the edge of the knife:
A Burr Projects from the Edge of the Knife
Now that you have your knife properly mounted in the sharpener, and your angle is set, it is now time to profile your edge and draw a burr from each side of the blade to ensure that both bevels meet. One more time, color your bevel with a marker. Slide your 100 / 200 Grit Diamond Stone paddles onto the guide arms. Using your 100 grit stones, make up-and-forward strokes against the knife until all of the marker is removed from the bevel.
Once all of the marker is gone, concentrate on one side and make an additional ten strokes on that side only. Carefully slide your fingernail or a cotton swab up the side of the knife (opposite the side you were just sharpening) from spine to edge. If you’ve successfully created a burr, your fingernail or cotton swab will snag on the metal overhanging the edge. Check the entire length of the blade to ensure the burr is present. Perform additional strokes as needed until the burr is obvious along the whole blade. Repeat the procedure on the opposite side.