stubborn nail from UE

[WRoy]

Can this be used as an adamantine improvised weapon in PFS?

[Sniggevert]

I'd probably allow it...once. After you remove the nail from whatever you stick it into, it'd turn into iron just like if you used it as it was intended.

[Mergy]

I'm looking at it, and it's basically a six-inch adamantine spike until it's pressed into something. Certainly once at least, as Sniggevert says. I'm not sure about a second time, but I'd err on the side of caution and say it turns to iron upon being used to stab a face.