Forged, or billet, What's the difference?

Question

I know what billet is, I thought billet was when a part comes from one piece of metal...but forged is more pricey. What's the difference.

Answer 1

A billet is an ingot of metal. The desired part is carved from the billet, and then polished. This process allows for some very intricate details, but since the metal is not strengthened beond the initial casting of the ingot, it may have weak spots.
Forging is taking that ingot of metal and heating and beating it into the shape you desire. This can be done with hammers, punches, presses, or molds. The process compresses the metal and makes it stronger throughout, as well as heat treating it for strength.
Good tools are "forged" and won't bend or break easily. Cheap tools are cast or cut.
For non-stress-bearing parts on a bike (air-cleaner covers, chromie bits, decoration), billet is fine. For a part that requires real strength (foot pegs, levers, mirrors, running gear), go for forged.
Cheers.

Answer 2

Short version without the book: Forging is a process using heat and pressure to form the piece. This aligns the grain structure, resulting in a stronger part. Billet is just a chunk. Cutting parts from a single piece is expensive, and looks nice but buyer beware. Strength can vary. The word "billet" is becoming generic, it's getting used for things that were not cut from one piece.

Answer 3

You have 2 very good answers here already. Imagine taking a cup of brown sugar (just scooping it out with a measuring cup) this would be similar to 'casting' the metal (let's say aluminum). Where, on the other hand, you pack the brown sugar in the measuring cup - this would be similar to 'forging'. As both previous answers stated 'forging' does add strength to the metal and in the case of aluminum, it also makes it a more quality piece of metal to beging with. Take motorcycle wheels for example - you can find 'cast' wheels and they may appear to be affordable. Or, you can look at wheels from makers like 'PM' and "Xtreme Machine" and they have MUCH higher quality.

It all depends on what the part is, what it's purpose is going to be and what you can afford as to whether you should go with 'cast' or whether you should go with 'forged'.