How about a bit of old school DIY.

Take one of the old bolts

Use a hacksaw to make a couple of diagonal cuts in the threads

Screw the bolt in to each threaded hole with a in / out / in out motion (don't force it in, just work it back and forth)

This should clean the threads with minimal cost and fuss.

That is exactly what I would do! the hacksaw cuts are a good idea in some cases, but these wheel bolts are hard, very hard, and making any impression with a hacksaw might prove impossible.

Now, I'm one of those unfortunate people who find the necessity to pick up road-kill when I come across it. I have picked up a small collection of exhaust mounting rubbers, a couple of very nice screwdrivers and even a lump-hammer shaped like a rugby ball. I've just looked through my collection of wheel bolts. I thought (but we know what thought did), I thought that they were all a standard M12 thread, but I see that some have a fine thread and some a coa***r thread. I can't get my M12 nuts to fit either. A 1/2" UNF nut screwed nicely onto the fine threaded ones but was very loose, so they're not Imperial. If anyone can illucidate as to what thread they're likely to be I would like to know. I like to learn something new every day!

Edit -- The forum seems to have censored one of the words I have used by replacing letters with asterisks. They might have found the word too coa***.

OK! The opposite of 'fine'.

Edited by MrEckerslikefromRamsbottom on 06/07/2016 at 00:07

Try c o a r s e!

It may be possible to find out the thread diameter and pitch from this website by entering you car details - it would appear they also sell wheel nuts and bolts.

www.performancealloys.com/wheel-nuts-wheel-bolts.a...x

And if you need a thread tap this little company is briliant - any thread anywhere.

www.tracytools.com/

Edited by focussed on 06/07/2016 at 17:41