Bonneville America Forums Forums Off Topic Discussion Forums Lounge Billet aluminum parts.

Just seen an advert on British Customs for "Billet aluminum gas caps" and wondered just what the general public thought what the word "Billet" means. The term "Billet" seems to be used a marketing ploy to entice the general public and to make them believe that"Billet" is a magic type of metal. Having been a machinist for 49 years and used to the term "Billet" I'm curious as to what people think it really is. NO Machinists are allowed to spill the beans, lets see how many different answers we get, this is only meant as an educational posting and not to meant to belittle or demean the layman and people not in the trade. I've seen so many ads about how something is made from a "billet". Whether it be Steel, Aluminum, Brass or whatever. Lets get some answers and educate ourselves.

At US Steel in Gary, In. a Billet is defined as a rectangular steel slab of various widths and thicknesses of new steel from the continuous caster. Whereas a Bloom is always a square length of steel created by a similar process. Boeing Aircraft produces several of their parts from alloys that would/could be considered Billets, but the direction of any rolling reduction process the metal went through during process is strictly noted by stamping and always stated on the prints as to which way the grain goes before machining. For a gas cap, a lost wax casting process would be fine and I would consider the Billet Descrpt no more than price enhancing hype aimed at the uninformed consumer.

I worked in a foundry for 25 years so I will disqualify myself.

I'd have said it's a block of forged material (aluminium, steel - whatever) that is machined to a finished item.
Suspension arm, handlebar riser, crank etc. Starts off as a solid lump then a computer controlled CNC machine(s) shape it.
Am I close?

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I am not a metal working. wish I could weld.

I think a billet is a processed metal blank that is ready to be formed. Blank stock.

That is my best guess.

My impression has been a piece which is first cast from a metal and then machined into the finished product be that with C and C or just polishing.

I always thought of it as a kind of superior stainless steel, as in an alloy that is harder and shinier

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.

having some experience in the metal working industry:

I would consider a billet to be any non cast, bulk solid of metal. I would also consider generic forging (but not near net shape ones) to be billets.

In general the term billet (at least in the US) is applied to non ferrous metals.

certainly parts machined from Al bar stock would be considered 'machined from billet'

FWIW - I have a drawing for the gas caps if anyone wants to machine out your own. I can email it, pdf or a cad format.

Billet means the part was machined, not cast in a mold or "printed".

Micah beat me to it!