Can I bore out steel wheels?

Our kia sedona for some reason comes with 6 x 139.7 rims which I am having a heck of a time finding in the correct offset and in 16". Junk yards are asking $80 a steelie which I think is a bit too rich. I have found that certain chevy wheels are pretty close but are too small in the center bore. I need 92.5mm. 

Is it ok to bore out these 78mm centers without compromising the wheel? I would likely do it with a die grinder and carbide or stone bit so it wouldn't be an exact round. Also there is a lip stamped into them, how much strength this contributes I do not know. 

I'm not sure where you are, but I think i paid closer to $50/wheel in Mass and the included the TPMS. 
 

Did you try searching car-part.com? 

I wouldnt bore out those wheels. 

I wouldn't do it.

You can usually get away with skinnier winter tires, I would rather buy some spacers that would allow you to run a different bolt pattern. 

Or just mount tires to your existing wheels. 

Monteros use that bolt pattern with a 108mm center bore.  Also 4 runners I believe with a similar bore. 

No Time said:

Did you try searching car-part.com? 

+1.  You should be able to do better than $80 a wheel.  Or for $80 a wheel, you should be getting factory alloys in good shape with tires on them already.

I wouldn’t do it...but have bored out Chevy truck wheels to fit my 4Runner, with a torch.  Ran them for a few years with no problems, somehow even managed to get another set of tires mounted on them.

I once tried stacking two hole saws, using the inner one to guide the outer one.

It did NOT go as expected, and I did NOT continue.....

That inner lip provides significant structure to the bolt circle. So don't do it.

Like Turnerx19 said, that lip provides support, so don't cut it off!

Reminds me of a story my Dad told me once, when he was faced with the same dilemma. As he was torching out the center lips on set of wheels he got a deal on, his Dad came along and told him "that wheel's gonna crack after a while if you do that", but as things usually go between fathers and teenaged sons, he thought to himself "what does he know?" and carried on with his little project...

Several weeks later he noticed there was a crack from each of the lug bolt holes to the center hub hole.

There are a fair number of 6x139.7 with a ~100mm center bore, you could use those and even use a hubcentric spacer ring if you wanted. You could also use a spacer only thick enough to make your new wheels clear the center bore on your vehicle, which might be 7-10mm. That might put you close to or past needing extended studs, though. 

If you're trying to find cheap wheels that will have that bolt pattern and a huge center bore hole, you'll probably have better luck searching for the inches equivalent  6x5.5 (139.7 is just a metric conversion of the old pattern which didn't actually change) , because most everything that still listed its bolt pattern in the inches version was an older 4wd something or other with the big center hole. 

Years ago my job moved me to Minnesota late in the fall.  My only car was a ‘94 Formula Firebird with summer tires.  I went online and ordered 4 steel wheels with Blizzaks mounted from Tire Rack.  They came in and the centers were too small.  I had to go north in just a few days though.  No time to send them back.  So I sat down with a die grinder and did just what the OP is asking about.  I never had a single problem with it but I only ground off about 2mm.  About a year later I got a letter in the mail from Tire Rack apologizing for selling me wheels that didn’t fit and offering a full refund.  I passed.  

I did it to put Toyota wheels on a Subaru but it was only a couple mm and left most of the ring. Sucked to do but worked. You'd be taking a lot.