Lock rock vs blade play?

[joeyza]

I was just thinking about this and wasnt sure if i knew exactly what the difference is. Am i right in thinking lock rock is when a framelock blade has vertical play and blade play is simply side to side play?
someone please enlighten me!

 

[PigmonkeY]

Thats how i've always understood it. Blade play = left to right
Lock rock = up and down

 

[bpeezer]

With lock rock, the lock is actually engaged with the tang of the blade. However, when you push on the spine of the blade, the lock will rock slightly to the left because there is not enough friction between the lock face and the blade tang. Lock rock produces vertical blade play, but the lock face is still engaged with the blade tang the whole time.

Also, you can have vertical blade play in a liner/frame lock without lock rock, but that's usually a sign of a very poorly made knife.