Further back in this thread was mention of Titanic being let down [no pun intended] by inferior rivets, and blaming that on the accountants. That may not actually be true, but this story is.
In the later stages of Rolls Royce's readying of the RB211 big fan jet engine for service [late 1960's] a very expensive cock up was laid directly at the door of the bean counters.
The compressor drum on these engines is made up from many discs in titaniiun alloy,. electron beam welded together at the narrow rim sections a little below the fir tree roots holding the blading. The process is carried out in a vacuum chamber and superb welds are the result. To prevent beam impingement onto the weld on the far side of the drum a sacrificial backing plate catches any 'blow by'
Unknown to the team at RR, after successful trials, plain mild steel backing plates were substituted in an attempt to save money instead of ordering the expensive titanium alloy versions. The result was that production drums were welded up and contaminated on the inside with a brittle eutectic alloy of 40% iron and titanium which was undetectable by both elecrical and magnetic methods.
It was found by chance to rust easily and that was the only way of reliably sorting out the rogues. I believe the entire batch were scrapped since chances could not be taken. The cost ran into millions taking lost lead times into account as well as scrapped materials .
Brian