u/TheSagelyOne

Why? Because a mechanic friend of mine requested one, and I'm a lunatic of sorts.

I have never made one of these before, so I have some questions. Does it matter whether it's mild steel or carbon steel? If the latter case, should it be hardened? And what's the best way to shape/size the head? My plan was to get the chonkiest 10mm bolt head that I can find and use that as a mandrel, but is there a better way?

I know it's an unusual item, and I know that my skill level is not very high, so any input from somebody more experienced than me is welcomed.

Thanks in advance!