9 Inch Nails

9 Inch Nails, is an American industrial rock band, founded in 1988 by Trent Reznor in Cleveland, Ohio.

But in the slang world, 9 Inch Nails is an SE, and a phrase. It's an innuendo for someone that has really long nails, like, actually nine-inch long nails. It was created by the same person who created the 96 Tears phrase.