The sides are made out of 4" channel and the cross braces or cutters are made out of 2.5"x2.5"x 3/8" angle. If the cutters begin to show signs of wear I can bolt or weld some harder AR steel to them. As far as angleing the scrapers go, I would think that the angled scrapers would have a tendancy to move the material to the sides which would help to fill in holes along the sides. But if there were no holes or ruts the material would build up on that side all the time leaving the finish on that side with more material. I didn't want that, thats why I made mine straight. There is enough space between the front and back scrapers that I could add a third cutter and angle it if I want. It is more of a resurfacing/leveling tool than an actual material moving tool. The material builds up in front of the scapers and disperses sideways, both left and right then flows over the angle and leaves a nice level uniform finish. I think if the cutters were angled the material would only flow one way, not both. I want it to flow both ways. The only thing so far that I would do different would be to weld the cutters so the cutting edge was about 1/2" below the bottom of the channel but I had them welded already before I found that out. But again it's easy to fix if I feel that I need that. I could see that being an advantage on harder surfaces but for loose material like I'm using it for, it works fine just the way it is.
Like mentioned earlier it is purpose built mainly for leveling black dirt when I landscape my yard and a bit of maintenance on my short driveway.
