I had enought his dull peeler for a little while. It hasn’t been sharp since the first day I bought it. I finally decided to but another one. The new one is sharp. I gentle slide the new peeler on the surface of an apple. The peel just separate from the pulp without much effort. The two peelers have different styles and blade coating. I was curious about why the new peeler worked so well while the old not so well.
I looked them under my stereo microscope. The width of the edge of the sharp peeler (~30 uM) was only 1/3 of the dull peeler. The dull peeler seems to have a flat surface on the edge (~100 uM). The thick and flat surface is the reason that my old peeler would not peel smoothly.