I was taking apart my front bumper last night and everything came off fine except the 2 M8's that you access through the holes in the bumper carrier. They're both rounded enough that my socket slips on them, any advice on getting them out?

 

Step 1: Get new bolts to replace these when you reassemble the car.

I haven't done this job, so I don't know exactly what you're dealing with as far as access. If you can get to the backside of the bolts, apply some Liquid Wrench or Kroil or whatever your favorite penetrating oil happens to be.

If the bolt heads are just a little rounded off, i.e. the socket tries to grab before slipping, you may be able to get away with applying valve grinding compound to the inside of the socket. This may give the socket just enough grip to do the job. This will work better with a 6-point socket than a 12-point.

Try using an SAE-sized socket that maybe just a hair smaller than the metric one. I'm not in my garage, so can't suggest a size - just look at what you've been using and experiment. Also, different makers have different standards for fit, so try a tool from another brand; you might find one that is just enough tighter to hold (especially in combination with the valve grinding compound.)

If that doesn't work for you, another option is to drill into the center of the bolt head and use a bolt extractor. Depending upon your access, this may or may not be a viable option. If possible, find a left-twist drill bit so that you're not tightening the bolt further as you drill the hole into the head. The bolts will definitely be scrap when you've done this. Plan to replace them.

Otherwise, plan on destroying a socket or two, so don't use your good ones for this. Instead, go with some from Harbor Freight or another el-cheapo tool vendor. You're going to use a socket that is slightly smaller than the original size; doesn't matter if it's metric, SAE, Whitworth, or whatever. You're going to pound this socket onto the head of your bolt until it has enough hold that you can remove the bolt. There's a really good chance that once you've done this, the bolt head will not come out of the socket, so be prepared to chuck the whole thing into the trash. If you're able to salvage the socket, so much the better, but you're still going to throw that bolt away. Under no circumstances should you ever use that bolt again. Repeat the process for the other bolt. Throw it away too.

Hopefully one of these will work for you; good luck!

 

Thanks for the reply.
I sprayed some pb blaster on them last night and this morning, going to give it another blast tonight and tomorrow morning then try to get it out tomorrow afternoon.

It looks like a half inch socket is just slightly smaller than 13mm so I'll try with one of them before I try any of the other methods you've mentioned. I'll report back on what was successful. I'm definitely ordering replacements for the reinstall.

 

Well after breaking 2 sockets that I hammered on I decided to try the duralast grip sockets as a last ditch before more drastic measures.
I was very pleasantly surprised when they worked perfectly and with very little effort!