The Cast Nut Case puzzle, part of the Hanayama Cast Puzzle series, was designed by Kyoo Wong and Oskar van Deventer, both renowned puzzle creators. The puzzle draws inspiration from the familiar industrial tools of a nut and bolt, making it instantly recognizable but far more intricate in terms of challenge. Unlike traditional tools, this puzzle has hidden mechanisms and tricks, requiring more than just twisting to solve. With a difficulty rating of 6 out of 6 stars in the Huzzle collection and 10/10 difficulty, this puzzle offers a moderate level of challenge, making it accessible for beginners while still engaging for experienced puzzlers.