Homemade Padlock With Screw Key

Check out my Instructable here: http://www.instructables.com/id/Padlo... This is a example of a screw type lock that as far as I could tell has been around since the 18th century and I came across some examples of this type of lock on eBay that were made in the 20th century. Lots of 19th century prison shackles use this design.