AR 400 works good but another solution Ive used on my old hoe and a few others is to get a grader blade edge from the county. lots of times they are worn off and not flipped over in time to use the back edge. I just measure off the unused edge to the middle and mark my line. most of the time I have to replace the bowed bottom I cut the whole bottom out and fab a new one. I usually order 5 inch by 1/2 inch loader cutting edge. About 78 dollars for 5 or 6 feet from SSB on there web page. Its all flat and prebeveled. som grader edge is curved and causes the bucket to suck in the ground or pile so you have to watch for that if you use it. Dont let SSB try to sell you the weld on bucket corners they are just pieces of the edge that are cut off and weled on just order a few extra inches.