Brian Dereu of Hollow Spy Coins showed us how to make this hollow dead-drop bolt for stashing secret messages back in MAKE 16. It’s not hard to do if you have access to the necessary equipment–a drill press, hacksaw, vise, grinder, and the appropriate taps and dies. But if you don’t have those tools, or you don’t have the time to use them, and you still want a spy bolt, Brian will gladly sell you one hand-made by his family and him for the not-unreasonable price of $37.

In the Makers Market: Dead drop spike

From the pages of MAKE:

MAKE Volume 16, Spy Tech! Learn how to build and use tiny surveillance devices, and how to know if a spy is using them on you. From tiny video cameras to sneaky recorders, this volume has enough cool stuff to make James Bond’s inventor Q envious. Don’t forget, subscribers can always read the digital edition here.