question for the group. I didn’t have a spare tire for the boat trailer and I happened to find a couple wheels that looked identical. When I got them home I noticed the lug nuts on the trailer wheels are counter sunk and the wheels I picked up are not.

is this something that I could drop off at a machine shop and ask them to machine out the wheel so it matches the one on the trailer? Anyone know what kind of machine shop would do this kind of work or of any in west Michigan?

Pretty much ANY machine shop would have the tools to do this; however I doubt any of them WOULD do it, due to liability concerns. You are asking them to modify a wheel that, I assume, has to pass some sort of DOT certification process by the OEM, which would be severely compromised by taking material away from what is frankly THE most important part of the wheel. I've worked in and/or managed a large machine shop that specializes in aerospace component manufacture for over 45 years, and on occasion we'd have one of the local farmers bring us some piece of farm equipment to duplicate or repair...and the first thing we'd do would be to have our Engineering guys look it over first. Another thing to consider is what it would cost you; I know where I work the shop rate is such that you could by four NEW wheels for the cost for us to modify those two. You are talking about several hours of work.
IF you are dead set on doing this, I suggest you find a local tool maker to make you an endmill with a pilot that would allow you to do this yourself. The tool could be made for under $100 if using cobalt or high speed steel.

Or, keep the spare wheels as-is and just get the correct lug nuts for them. What you have are conical seat wheels on your trailer, and mag seat spare wheels. Trailer studs are commonly 1/2”-20 thread, so go to your local auto parts store and pick up 10 mag seat lug nuts. These should have washers with them, which you need to use with the nuts. Also, mag lugs are made with different length shanks, so bring a wheel and make sure that the shank doesn’t protrude past the hub mounting surface.

Ayuh,..... That wheel looks like a uni-lug, multi-bolt pattern wheel, as the holes are slots, not round,.....
They take special washered lug nuts,....

Just a little more expansion on that, not only washered but also shouldered lug nuts.
As in the 2nd and 3rd from left in the top row.
Hate to see a guy just pop some washers under the nuts when they need the shoulders to "align" the wheel.

Bajaman,

The lug holes are oval, not round. A piloted counterbore will not work.

Swellcraftman,

I'd be more than willing to do the work, just as long as you forgot who did the work before you got back on the highway. I'm also doubting you'd be willing to drive all the way to Dayton for an hour's work. You should be able to find someone in MI that would be willing to do it. Personally, though, I'd take the advice and get the proper lugnuts for slotted wheels.

Thanks. Brad.

Thanks everyone for the help. I talked to a tire shop and they are going to get me the correct nuts as is.