So there is a half size? I know there is some kind of socket to fit the bolt I am trying to get out but everything I have is too big or too small. Trying to get the stock stereo out of my '89 full size Chevy truck and I ran into 4 of these nasty little things and I'm out of my mind.
There are only a very few metric half sizes and only below 10mm. Most metric socket sets I know contain them but I have hardly ever used them even though I live in Europe where metric sizes are common. I think hose clamps sometimes have half sizes as well.