I split a winged elm night before last, about 10" on the butt end. 90 degrees of twist running 40" of it's lenght, and the other end (40" as well) straight as a string. I think I'm gonna part it in the middle and leave 4 sets of billets. Winged elm is the one wood I've found that is as naturally knarly and wretched as osage. Vine maple or Guava may be the only other two, but not native to our area. It was an absolute beast to split. Folks who complain about splitting osage ain't obviously ain't fooled with elm. But I love character wood, so I ain't skeared.