Production of these custom double thread lag screws for our construction customer was run in batches of 50,000 pieces using medium carbon steel material with zinc + clear finish.  Overall length measured 10.75″ +/- 0.20″ and 1/2-6 lag screw thread was incorporated at one side, with the other side using rolled 1/2-13 thread.  Approximately 5.5″ of lag thread was designed into the part and 1.2″ of the machine screw thread.  The crimped shoulder was set to a height of .37″ +/-.02″ and a length of .625″ to allow use of a wrench during the application.