ok, i'll jump in too....
a "tenth" is not anything.... its a part of something. What it "usually means" depends on who you are talking to.
when talking to a machinist, or about machined engine parts, a "tenth" is assumed to be .0001 inch, just like a "thou" would be interpreted as a "thousandth of an inch", not a thousand inches..
say a "tenth" at a race track, and it is assumed to mean .1 second. (or it could mean that 9 guys finished before you)
since we were talking about connecting rod bearings, wrist pins, etc. the nomenclature was valid.
i could go on, but this thread has gotten really far off track.
apologies to the original poster, I am very interested in the outcome of the analysis of the failed rod. (does anyone need clarification that I am referring to a "connecting rod"....?)
Back under my rock....
Bob