Hrm.. never knew that. I've made many things from bed frame angle iron. I just recently build a welding cart out of one to save $300 I picked up off of the side of the road ready to be picked up for trash. The welds seem to hold well for me though, but I've never put it to the test. But holding up so far fine. I use flux core, so not sure if that matters or not.Be careful using bed frames, they are heat treated medium carbon steel and if you don't anneal your weld they will crack and break eventually. I try and get the weld and surrounding area red hot while welding by making a large hot puddle and it seems to help on the cracking. If you don't believe me take 2 pieces and shoot a quick cold butt weld and you can easily break them apart after welding which will show you that the steel is brittle at the weld.