So I was playing around this morning and I always put a tiny back bevel on my plane blades. There's no point in putting the entire back of the blade on a stone while the only thing that matters with a bevel up blade is the edge. I use a small 1.2mm thick strip of Formica to raise the blade a tiny bit. Anyway, I was planing some end grain with my low angle block plane and I thought to myself: "What would happen if I sharpen the bevel to 25 degrees and put an 8 degree back bevel on the blade to strengthen it?" So I took a spare blade and I sharpened it to 25 degrees and I put a 8 degree back bevel on it. Well, guess what... this gives you an edge that's a lot more durable because now you've effectively created a 33 degree bevel on the blade but the angle of attack is still 37 degrees on a low angle block plane.
