I kicked up a few of these old square bolts and other junk a few weeks ago. One of these looked like it would be a good flatter, so I tried to make one. Its a non handled version, a little on the small side but it works for what I needed. After I made it someone brought it to my attention that I should have forge welded it. I'm such a failure at forge welding I didn't even think about it. But maybe if I make another one. Video'd making it for kicks, basically just me wailing on it with a sledge hammer. I do try it on a knife blade at about 3:48. Another one of them was a domed bolt with "R S C" on it. I was told it might have something to do with the rail road. I used the suggestion I got here and soaked it in water for about 3 weeks. The rust came of pretty easy. Hit it with a couple of flap discs. Not polished but it was getting close to eatin time, I might buff it up more later. Thought it might come in handy for something as a stake or hardy tool. It has to be close to 2" across. Been a while since I was able to get out to the shop, had a good time.