He 'walks a/the razor edge' [='walks a/the fine line'] between humor and bad taste in his comedy.
It was a 'razor-thin' victory. [=a victory that was won by a very small margin or amount]
He's a thrill-seeker who likes living 'on the razor's edge'.
(..) what happens is it mushrooms. When it mushrooms it peels back. So you may have six, eight... ...ten little particles of the bullet that are like razor blades... Sir, yes, sir! ...tearing their internal organs, their liver, their lungs, their heart... ...bringing tissue, bone, blood, (..)2006 The Departed