Tern Key (2022)

Tern Key is Pit Khiam's sequel to his earlier Binary Key II design. The goal is to remove the sliding key from the frame by manipulating the internal pieces. Complexity is significantly increased by expanding Binary Key's locking mechanism into a trinary design. This yields a hefty 134 move solution with four locks to defeat in sequence.

This is our first release of both Binary Key II and Tern Key since 2013. For this release we have modified the design with slightly thinner extruded acrylic middle and top layers for better operation. We also added a thin spacer layer to ensure smooth internal movement, and replaced the metal key pins with acrylic for more reliable press fitting and retention.

Precision cut from solid acrylic and painstakingly hand-assembled, Tern Key has a nice weight and feel. It will not be confused with cheaper mass-produced take apart puzzles!

Construction uses contrasting press-fit dowel pins to align the internals.

Here is an excellent blog review of Tern Key. Another review of both Binary Key II and Tern Key may be found here.

Pair this with Binary Key II for an ideal sample of grey-code style puzzles in your collection!

Previous Releases:

• Tern Key (2009)
• Tern Key (2013)