Question: Brass bands were being discussed today which naturally led to someone claiming to be *brassed off* about something, meaning disgruntled or annoyed. Does anyone know the origin of this expression? Michael Quinion over at [World Wide Words](http://www.worldwidewords.org/qa/qa-bra2.htm) suggests the phrase may have arisen from the Royal Navy's use of cleaning brasswork as a punishment, but that doesn't seem altogether convincing.

Answer: 
The OED reckons it came from "Service slang", and cites 'browned off' as a comparison. The earliest use there is 1941; taken together with the Ngram, this leads me to believe it arose suddenly and untraceably, as slang does, among the troops (probably the RAF, who were very inventive in such matters), and proved so useful it spread everywhere.
My understanding of the phrase is that it originated from the practise of sharpening an engineer's twist drill. The sharp cutting edge was dulled. Otherwise the sharp cutting edge would bite into the brass and chatter. If the cutting edge was removed it could cut into brass sheet or solid bar without any trouble. Hence the drill had been brassed off. I cannot see the connection between the usual understanding of the phrase as in hacked off, pissed off etc.