1.0   Keyed brick videos of four types of connections: key thread, thread sets, multi-axial locking and its shape.

Click on this video to see key thread and thread sets

This video is an assembling bricks to show multi-axial locking

This video is a side view of assembling bricks side view of multi-axial locking

Walls have vertical strength. This video is a lateral strength demonstration (200 lbs or 90 kg)