There are two goals to the Cast Nutcase created by the Dutch puzzle inventor, Oskar Deventer: 1. Remove the small nut by disassembling the Cast Nutcase. 2. Cast puzzle enthusiasts (nutcase) can enjoy trying to change the wording on the bolt from "nut-case" to "case-nut." The key word is "interlocking."
Hanayama is known worldwide for challenging puzzles and quality manufacturing. Can you take the pieces apart, then put them back together again? Hanayama cast metal brain teasers have 6 levels of difficulty, and each puzzle is Mensa-rated. Level 6 puzzles are considered very difficult by most puzzlers.