If you're talking about the screw in type, they are made in stainless. I have both the wood thread and the machine thread. I believe they came from Brownells years ago.
As for the recessed installation on a wood stock.... I'll assume you're referring to the "flush cup" type. When I install these, I mill the stock to a diameter slightly smaller than the cup, then glue and screw them in. The cups are threaded.
If I'm off here, please be more specific on the type you're referring to.
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