Why brass over aluminum?

[Roger11]

What advantage is a LED light that is made from brass over aluminum? Heat dissapation? To me the lighter weight of aluminum is a definite plus?

 

[FluffyGrunt]

I think it's mainly for looks. /ubbthreads/images/graemlins/cool.gif

 

[karlthev]

Yes...appearance is the key in my opinion as well.
/ubbthreads/images/graemlins/icon6.gif
karl

 

[Mrd 74]

Aluminum will need the threads lubricated,not necessary with brass.

 

[Archangel]

Brass will sink the heat better, though that's really only an issue when you start putting luxeons in really tiny packages.

 

[Silviron]

Brass is actually a rather poor heat sink.

Silver is best
Copper is second best
Gold is third best.
Aluminum is about 5th best,
Brass is a couple of steps below aluminum in terms of position on the list, and approximately half as efficient as aluminum in sinking heat in quantitative terms.

Here is a chart:
properties_of_metals

 

[Mrd 74]

Silviron
Thanks for the link,very "enlightening". I was under the same impression as Archangel.

 

[raggie33]

u sound corect ron i like copper but i guess it would be odd light

 

[Archangel]

(smirk) We're both right - i was thinking keeping it away from your hand, not pulling it away from the LED. Brain-fart and all that.

 

[tvodrd]

It's a little more complicated when you factor in specific heat and density. Specific heat is the amount of energy required to raise the temperature of a given mass a given amount. Thermal conductivity rules when you are extracting a lights waste heat to your hand, but the light's temperature has to rise to above that of your hand for thermal transfer to begin. With otherwise identical lights of aluminum and brass, the brass light will heat to equilibrium temperature a little slower due to having ~3x the density balanced against aluminum's a little over twice brass's specific heat.

What I find amusing is the "premium" brass lights seem to command in relation to the retail price of the material. A 3 foot stick of 1" dia 6061 T6 aluminum will cost you $15.83 vs $43.41 for 360 ("yellow") brass from McMaster. So how much was the actual material cost difference for your 1" dia by ~3" long flashlight? IMO, I find 360 easier to machine than 6061 T6. Machine shops buying in larger quantity probably get the material at ~1/2 McMaster retail. I'm sticking to HA aluminum lights with copper centers. /ubbthreads/images/graemlins/grin.gif

Larry

 

[Anglepoise]

And don't forget that brass starts to tarnish the second after the last polish. Not good especially where knurling is involved.
Brass is for show only.

 

[TORCH_BOY]

Cosmetic, looks great

 

[OddBall]

Is copper hard to work???

 

[Flying Turtle]

Love the smell of brass tarnishing.

Geoff

 

[Silviron]

[ QUOTE ]
OddBall said:
Is copper hard to work???

[/ QUOTE ]
Depends on what you mean.... "Pure" copper is very soft so it is easy to work....... But a little difficult to machine because it acts kind of "sticky".

Chips from lathing & milling tools can tend to "bend around the edges" rather than come off cleanly.

Amazing what difference adding a little zinc, tin, aluminum, or beryllium to copper will do: Makes it nicer to machine and 'ruins' its thermal and electrical conductivity.