Several "health food" stores near me have a machine that grinds fresh nut and butter. Two such stores are Fairway and Whole Foods. The nuts are grown in California and Georgia (the U.S. state, not the country.)
I asked the manager in both places about the nuts and the machine. The nuts are raw, except where noted otherwise (i.e., some machines have roasted nuts.) The machines are used only for the nuts. From what I can tell, it is a closed system, i.e., nothing else goes into the bin or the grinding mechanism except these nuts. If it makes any difference in the answer, the ground nuts come out a bit warm, probably due to the friction caused by grinding.
Can one buy this product without needing kosher supervision? If not, what concerns might there be?