1993 4g63 head bolt question

[KazooGS-T]

Ok, so I go to remove my head off of my 1993 Tsi Awd project car. Take off the valve cover, etc. and everything goes just fine. So I get to the head bolts, well I go and put a 13mm 12-point on, and it's too large; so I step down to a 12mm 12-point and it's too small? So then I go and try a 1/2in 12-point, too large again, step down to a 7/16in and guess what? It's too small. So I am trying to figure out exactly what size bolt this is that hold the head on. I know that something isn't right with this picture, so please someone tell me what size the bolt head is.

 

[delta448]

I'm pretty sure they're 12mm...

 

[KazooGS-T]

Problem resolved. Make sure and use a deep well 12mm socket, I decided to just go out and buy a deep 12 and deep 13 and the 12mm worked perfectly, the sockets that aren't deep well will not fit. (I always used a 12 point socket, in both situations)