I have used the DPMS AR15 Armorers Wrench for years, I have owned several of them. I gave some away, I broke a few in half hitting stuff, but I have never had one break on me until recently. I was toying with the idea of installing a Fortis Switch handguard I have on an upper and I went to tighten it up, then the dimple on the DPMS tool came right off.
Thankfully it was only $8.00 so I do not feel too bad about it. I instantly went online and ordered a Magpul Armorers Wrench since I have heard good things about it. Check back, I will report on it when it gets in.
Since that sucked and now that I have the barrel nut tight enough on the upper that I cannot remove it by hand I went to a local shop and picked up a very cheap AR15 wrench. That did not make it either, I could not even get the barrel nut off, the wrench just turned into this: