Anyone know what makes aluminum "billet"? I see it constantly for parts, but know nothing about it. Is it an actual alloy, or just a treatment?

 

Dictionary.com says:
b) A small ingot of nonferrous metal.

Typically, it is a part machined from a solid chunk of metal, rather than cast or manufactured in some way.

 

Good answer, and to add to that...

Aluminum itself is an alloy, nonferrous (no iron content). So "billet" does not refer to any changes in the alloy content of aluminum, but instead that the refering part has been machined from one solid piece of aluminum.
Randy

 

Well, that'll answer my next question about machinablility of it....haha

 

Yeah, aluminum is easy to machine (most alloys), doesn't rust, and looks cool. For the ultimate, why not go 'billet titanium'?

 

true machined titanium cost a fortune due the extreme cost in cutters and intensive man/machining hours involed.
there have been a surge in "titanium" alloys though.

 

Yeah, I've had a few tennis rackets w/ titanium, becoming a popular alloy in many areas.

 

Aluminum is an element on the periodic table, #13. It's not very strong in it's pure form but it's properties can be changed by making alloys using various other metals.

 

I would not say machining alumunum is easy. Aluminum tends to be gummy when machining and can stick to cutters causing gauling. Most guys would rather work with tool steel than aluminum. Once someone masters aluminum machining they don't have a problem though.

 

Here's a tip- if you're drilling aluminum, WD-40 makes a great coolant/ lubricant. BTW- aluminum was once very rare. There is an aluminum cap on top of the Washington monument- a real rarity in its day.

 

Tip #2 - Aluminum = 2-flute cutters!!

 

The term billet is originally used by the metal producing mills to describe a general shape of raw metal. It applies to aluminum and steel and other metals. Starting with the ingot (the result of the molten metal poured into the giant mold), the ingot is hot rolled into "blooms" which are about 6" x 6" cross section. Rolling involves squeezing metal between a series of rolling pins to crush the shape to the desired size. Blooms are then rolled to billets which are typically 1-1/4" up to 6" cross section. The term "hot rolling" means the metal is worked at an high temperature like what a blacksmith used to do. Metal can also be cold worked (like Weld Wheels and BBS Wheels who advertise cold forging).

Most of the "billet" car bits we buy are made from extruded aluminum rods or cast plate. But the term billet is used by the aftermarket to mean something machined from a solid chunk of metal instead of the part being cast, forged, molded, stamped, etc.

With modern equipment, aluminum is about the easiest metal to machine. Very low power consumption and can be cut at very high speeds. In fact, I just finished making a bunch of "billet" interior pieces for Mental Addiction Motorsports (http://www.mentaladdictionmotorsports.com/cart/) on the CNC milling machines in my garage.

 

Haha, good call. I was at school in machining lab justa couple days ago and used a 1/2" 4 flute cutter, and man, the aluminum basically melted to the bit, still trying to pick it out.

 

Spray mist will keep the cutters and drills from gumming up during heavy cuts.
steve