Question about frame lock?

[stockae92]

Why does most of the frame lock engage only part of the spine of the blade only instead of the whole spine of the blade?


like this

blade spine

. | |
. | |
. |__|
|--|
| |
| |

frame lock


instead of this

blade spine

| |
| |
|__|
|--|
| |
| |

frame lock

 

[carrot]

There is a very good reason for this and it is not readily apparent until you use a frame lock (Chris Reeve Integral lock) for awhile.
Since the locking surface and the tang of the blade are constantly being rubbed against each other (locking and unlocking action) the surfaces will eventually wear down, some faster than others, depending on the exact geometry of the mating surfaces.
Because they are not fully in contact with each other this allows for the lock to self-adjust as the mating surfaces get worn down. Otherwise there would be nowhere for the lock bar to move over and the knife would eventually develop vertical blade play (bad).

 

[stockae92]

ah i see

would the frame or blade be worn down to a level where either one needs to be replaced so that they are play-free?

(maybe especially with something like a S30V (hard?) blade and a Ti frame lock (soft?))

 

[carrot]

It is possible that it could be worn down that far. But instead of replacing the blade or frame it is more likely that a slightly larger stop-pin would be used in place of the old one.