I don't know if this will be much help. I usually use a grinder for sharpening machetes, axes, bush axes, lawnmover blades, etc. As long as you do not get the blade too hot it is fast and easy. If you do not have access to a grinder then a double cut bastard file will work fine. When using a file start with a coarse one to remove stock then finish with a finer file, stone or diamond. I use a wider angle on the edge than knives, usually 20 to 25 per side. I will sharpen many tools the same as my knives(8 to 15) if I am using them. When sharpening for friends who tend to hit rocks, dirt, bricks, or houses the wider angle is used.