I see the word billet thrown around nearly everywhere. The dictionary definition says billet means to quarter a soldier in a civilian structure, or a small block of wood, or a small bar of steel, iron or other non-ferrous metal. What does it mean when used in the context of truck parts? I'm guessing it means a part that is machined or forged instead of cast. It seems the word is often misused.

I've got a question for anyone with some metalurgy knowledge. Is it possible for a cast part to be as strong as a machined or forged part if the environment in the casting process is controlled? I mean, the blocks that parts are machined from were once poured as a molten substance just like in a casting process right?

 

Billet IS often misused. A billet part should be just that, milled from a solid piece of aluminum or steel. Billet wheels are usually cnc'ed froma billet blank or block.

 

Billet means that it was machined from a solid billet (the billet will have been rolled or forged, not cast) of metal. If it was cast it would be called an ingot. Forging is a process where the material is hammered into shape. Finish machining will be required as it is not very precise. Forging is the strongest way to form a part because the grain structure of the metal follows the shape of the part. Rolling is exactly what it sounds like: metal that is forced between two rollers. When the metal is rolled the grain structure is aligned and any voids are filled. Casting is the weakest way to form a part. Castings are prone to voids, inclusions (stuff that shouldn't be in there), and core shifts. These are all weak points. Castings can be adequately strong for many applications assuming they are engineered and manufactured well. Many car engines have cast cranks and connecting rods.

A comparative example: Ruger revolvers have cast frames, and nobody complains about them being weak compared to a S&W. The Ruger frame is bulkier - it has to be to have equal strength to the forged S&W part.

 

Some people see the word billet and pay top dollar for it because they think it is better than the package that does not say billet. It's just a way for companies to push products.

 

wannadiesel, that's a good definition. This is a very good question that I wonder how many people who buy billet parts really know the definition of.

 

So, a billet grille for our trucks, starts out as a solid piece of metal, then small strips are cut out and polished, bolted to a frame and sold as "billet grilles"?

Hay

 

Cast parts exhibit low strength and ductility as compared to the wrought form of the metal in question. Porosity and shrinkage are major defects that can be present in cast products, which usually cause them to fail without warning.

Strength in casting can be improved by using different melting, mold making and pouring techniques- which will help reduce the number of inclusions / make them less harmful.

The solidified casting can also be heat treated to remove residual stresses, gain uniform material properties throughout, or to gain the optimum crystalline structure. These all help getting desirable properties.

It is correct to say that blocks that parts are machined from were once poured as a molten substance, but they are worked to "beat out" any porosity or casting imperfections. Your left with a metal specimen with a uniform crystal structure in a semi-finished state (plates, bars, etc.)

 

I am so glad no one said it is a type of metal!

 

I agree with most of the above statements, however I would add that just because a part was machined from a forging does not necessarily mean it can be called "billet". Most typically, a forging is made from raw material, from the mill, and is formed into roughly the shape of the finished product. Final machining, grinding, etc. most likely has to be done to it to get the finished product. An example of this would be a connecting rod or a crankshaft. On the other hand a "billet" part would be one that was machined from a solid piece of material, that came directly from the mill it was produced at. The virgin stock might be flat, block, or cylidrical shaped, but would not resemble the finished part whatsoever. As stated, above custom wheels are an example of this. Also, billet partsmay not be as strong as forged parts, due to the grain structure not being oriented to the shape of the part, and billet parts typically have a lot more waste associated with the machining process as well.

 

The aftermarket "billet" grills for most trucks are cheap pieces of metal strips painted or chromed on the outer surface to look like pollished billet aluminum. A true billet grill of aluminum would be more expensive than the 40-80 bucks most cost.

I think anyway, since mine was el cheapo. but looks good.

 

Its a type of metal

 

How so? Does this mean that the non-billet, $2500 aftermarket trannies for our trucks can hold up to 700hp like a full billet tranny that costs nearly 3 times as much?

 

Some parts in your oem trans are from billet - some are from forgings - some are from castings - some are from stampings - just like those "billet" versions

One major difference is how much 'stock' is removed to make the finished piece - or, how much stock was not removed in order to increase strength.

Another is if and how the piece was tempered or hardened to increase strength.

But, all any vendor has to do is label the item as 'billet' and - well, PT Barnum would greatly relish the cause and effect of labeling something\anything\everything as 'billet'

 

You mean it's not?

 

I'm so glad someone else understands that billet isn't as strong as forged. I've gotten into arguments in the past with gearheads about this. You know, some guy talking about this awesome billet crank in his engine... And I try to explain that they made it out of billet because sometimes getting the shape or stroke needed is impossible with a forging, not because its stronger than the forging...