Well, i've opened a can of worms with this one. Just looked up "Billet" in the machinist's handbook and can't find it or maybe i missed it. My version #27 has 2693 pages and i found all kinds of new things to boggle my mind with..
To me a "billet" has always meant a short "slug" of metal approx. 13" long that's been cast in a foundry and can be any type of metal, Brass, Steel, Aluminum, Copper or whatever. According to Ryk and i see no reason to question his input seeing as he probably worked where they made it i stand corrected.
I've only ever machined the stock not made it and the gas caps shown were round so probably came from round bar stock.
Bar stock is a more homogenous material than a casting to me as it's rolled to size.. Casting can leave voids or even have slag pockets in it and a forging is hammered/ squeezed/ pressed to size and is a denser and stronger material than rolling or casting is.
Machining of a billet can be done on a manual machine like i did or by a CNC ( computer numerical controlled) machine.
jamesbrown was in a foundry for 25 years so he also knows different terminology.
It's amazing to see how many different opinions there are for the same word so i'd better stick to cranking handles (when i feel like doing it) in my retirement.
