by David Swearingen » 9 Aug 2006 5:03
To answer kinerry's original question, you go by the letter(s) at the bottom of the bow (head end of the grooving). The key is "M" keyway; "CB51" is the key number and designates this key as the 51st servant key under the CB submaster, under the C master key. Almost all Best keys have the keyway designated in this manner, although certain large users specify that the keyway letter be ommited from their keys.
The "LM" key was specially milled by Best to enter both the L and M keyways. Best considers the "JKLM" keys a family, meaning that any two or three of these keyways, or even all 4 of them, can be combined in the same GGM system by milling special keys to enter those keyways. Their terminology for this is "double-milled", "triple-milled", or "quad-milled" depending upon the number of keyways the specially made keys will enter. So far as I know, "JKLM" was the only set of four keyways that was specifically designed as a family. Other double-milled and triple-milled combinations have been made (DE is the most common), but they were an afterthought and not originally planned to be used together. When I have time, I'll write a complete story about the history and development of all the Best keyways from A to Z.
We are all born as originals. Why do so many of us die as copies?