Brass Bolt puzzle

Updated STL Files, Exported with 1mm per unit
This puzzle you can either 3D print or make using some M16 & M8 Brass nuts and bolts, you will also need a 4mm x 2mm round neodymium magnet. and a 10mm x 4mm steel rod (cut a piece of 4mm nail)

Thanks to Grabcad User Heatniks for the original bolt and nut drawings.
http://grabcad.com/heatnix

The origional idea for this puzzle is based on a puzzle from "homemade puzzles"
http://homepage.ntlworld.com/bruce.viney/Bolt%20Puzzles%20Secrets.p