The cornerstone of hand tool woodworking is the chisel. Whether you are chopping dovetails, paring to a line on end grain, or shearing off a bead of excess glue, one thing is for certain, you will want that bad boy to have a hair-splitting wicked sharp edge on it. The concept for how to sharpen a chisel is straightforward; bring two metal planes to a fine point at a defined angle and keep that angle honed as you use the chisel.
The problem is that a full bevel that needs to be honed is quite long, requiring the time-consuming removal of a lot of metal to maintain the sharp edge. What can we do about this, you ask? Well, there is neat technique available to us that allows us to hone only a fraction of the overall bevel, which lets us spend less time at the sharpening bench and more time building our projects. The approach is to form a micro bevel at the working end of the chisel. A micro bevel is simply a small portion at the tip of the chisel that is angled slightly differently from the primary bevel surface.
The advantages of using a micro bevel rather than maintaining a single bevel include:
Easier/Faster sharpening. Honing a tiny portion of the overall length of the chisel tip takes a fraction of time compared to sharpening the entire thing.
Easier to change angles. Different tasks can be performed better using different chisel angles. If you want to optimize your chisel angle based on the operation at hand, or just experiment with different chisel angles to see which one you prefer, it is far easier to modify that cutting angle of your chisel if you have incorporated a micro bevel, as there is less metal to contend with.