I'm glad this question was brought up as I have often wondered about this myself. Although the explicit warranty with ESEE is nice, I like knowing that others have had good experience with KA-BAR customer service.
if one were to dig into the threads, looking for the word "break" perhaps... one will find some examples of broken blades, and afaik, they were ALL replaced. none were found to be abused. sometimes "stuff" happens.
iirc, Becker/KaBar considers *proper* batoning to be normal use. note *proper* as mentioned earlier... if you try to baton through rocks or cement, or use a pipe, or rebar, or a hammer, or clamp the blade in a vise, or other "testing", that's abuse...
personally, i wouldn't want to baton through certain kinds of evergreens or other woods with nasty knots. clean wood, clean times.
i think "in the history" of Beckers and breaking...
BK - Reinhardt - - a couple as victims to frozen Xmas trees
BK1 - Brute - a couple older models, not Camillus ones
BK2 - Campanion - none broken
BK3 - TacTul / TacTool - one one, 650 pounds of gorillas :>
BK4 - MacAx - maybe one
BK5 - Magnum Camp - none
BK6 - Patrol Machete - maybe one or two, also Xmas trees
BK7 - Combat Utility 7 - one or two?
BK77 - Combat 7 Extreme - none
BK9 - Combat Bowie - maybe three or four
BK10 - Crewman Utility - none
BK11 - Necker - none
BK11 - Necker SanMai - none
BK13 - Mini Necker - none
whee?
Bladite