I'd been working on a bow saw, but got stuck figuring out how to attach the saw blade to the frame. I sat on it for a while, and then finally came up with this solution. I sawed the threads off of a couple of 5/8" carriage bolts. Then I cut slots in the ends of the bolts, and drilled a small hole in each for a small machine screw to hold the blade in place. A nice feature is that I can turn the bolts 90 degrees, so that I can use the saw to rip through a long board if I want to.