Uploaded April 2026 | Updated September 2026, 1 day ago

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A pretty exhaustive deep dive into an iconic Brown Belt lock. I explain its design requirements, history, a description of the internals, a comprehensive picking guide, and a worked example picking video.

I'd like to make the point that this is not an easy lock to disassemble and then reassemble without damaging springs and deforming the thin brass retaining strip. If you're looking for a lock to film for your LPU brown belt requirements...this might not be a great choice.

0:00 - Introduction
0:41 - What job was it designed for?
3:52 - How does it work?
6:49 - Pins - overview
8:25 - Pins - keyspace
11:34 - Pins - in detail
14:15 - Picking tutorial
16:45 - Choice of picks
18:57 - Choice of tension tool
20:45 - Picking algorithm
27:19 - Picking recap and overview
28:34 - Picking starts
31:57 - False set in groove 1
35:19 - Final comments