What is billet?

[RobertN]

What is billet, as compared to other aluminum alloys? I have a Harley, and see all kinds of billet accessories. I saw the post yesterday about a billet torque converter for a diesel pickup.

I did a web search for infromation about billet, but came up with mostly supplies or products(like mirrors, cam covers ect).

I was more interested what billet is, how it compares to other aluminum alloys, is it cast, extruded, or? What makes it so nice for rims, mirrors, torque converters, ect.

 

[beenthere]

I believe it refers to the solid piece of machined metal, like from a billet. I don't think it is an alloy.
Did you search "billet torque converter" to see the hits for links to these converters? Some discussion of the 'billet' there also.

There also is a guy involved by the name of "Billet" and he may be designing parts that are named after him. Bill Billet's name comes up.

 

[scott_vt]

Hi Rob,
I get a charge out of whenever I see something advertisesd as made from billet. Probablly because I have been fabricating parts for 34 years out of all types of material.

To me it means nothing more than machining a part from a solid block of material. Whether it is aluminum or some other alloy. The Harley mags must have a TM on the term /forums/images/graemlins/grin.gif

OK, aluminum comes in a number of different forms. In bar stock, whether round or square and rectangular, we usually get 2024 or 6061. On the chopper shows were they machine the rims from scratch, I believe they are using 6061, mostly for the strength. Aluminum sheet stock that we use for bending, we use 5052. My son has a Harley and he asked me the same question, thats why I had to chuckle.

Hope this helps.

scotty

 

[RedRocker]

Billet is one of my pet peeves. A billet is a block of metal, nothing special about it, doesn't denote any alloy or secret compound. The Harley world is et up with the term and it drives me nuts. Now the Jeep world is using it for their parts.
Billet Billet Billet /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif PR Hooey!!

 

[midlf]

What billet means to me is the part is way overpriced cause they had to do so much machining and throw so much metal into the scrap bin.

 

[mikim]

<font color="blue"> What billet means to me </font>
is where I'm sleeping for the night .... must be that pesky 21 yr military thing again /forums/images/graemlins/tongue.gif

 

[3RRL]

Robert,
These guys are all right. I especially like RedRocker's statement </font><font color="blue" class="small">( Billet is one of my pet peeves. A billet is a block of metal, nothing special about it, doesn't denote any alloy or secret compound.)</font> and what midlf said </font><font color="blue" class="small">( the part is way overpriced cause they had to do so much machining and throw so much me)</font>

A billet is a solid piece of material as explained by scot vt. Parts are machined out of that bar stock. It is most commonly used to differentiate from a "die cast" aluminum alloy. In which the aluminum alloy (typically an A380 alloy or similar) is poured into a mold and out comes the cast (molded) part. Sometimes, but rarely, the cast parts have some porosity or small inclusions in them from improper molding or cooling. The parts are usually inspected via x-ray if they have some significant engineering task to do.

Some people think billet is better because the billet is extruded to remove any porosity and it is more uniform. 6061-T6 and 70-75 aircraft aluminum are examples. Therefore their mechanical properties are more reliable and consistant that die cast components. Parts that are not mass produced and require certain strength characteristics (as opposed to millions that come out of a mold) are good prospects for "billet" aluminum parts, because they have to be completely machined.

Many die cast parts are machined after being molded and will look just like a billet machined part. Flat machined surfaces or drilled and tapped holes for example. Most die cast parts will hold up to many applications. Look at your aluminum engine blocks, heads, housings for chainsaws etc. Just depends on what strength you want your part to be. Design engineers calculate that out for their specific applications.

 

[kenmac]

Most race car engine builders prefer a billet crankshaft over a cast crankshaft. I have seen many cast cranks break in race engines. They are fine for every day autos.