Brass sleeve

[Tekno_Cowboy]

I have a flashlight with a brass sleeve on the inside of the battery tube. The outside is HAIII. Can anyone tell me why a brass sleeve might be used?

 

[gadget_lover]

HAIII is an insulator. The brass is used as a huge conductor.



Daniel

 

[Rothrandir]

What flashlight is this?

I can't imagine why it would use brass as a conductor where aluminum does a swell job itself...

Are you sure the inside isn't aluminum that has been through an alodine process?

 

[Tekno_Cowboy]

It's a Wolf-Eyes Raider. It looks like the Aluminum was anodized inside and out, then had a brass sleeve pressed in. Dealer says brass. It appears to be brass. Are the thermal or electrical properties of brass improved over aluminum?

 

[LukeA]

The only thing I could see is if brass has lower contact resistance than the aluminum oxide layer that will build up on bare aluminum over time.

 

[Tekno_Cowboy]

come to think of it, isn't aluminum oxide an electrical insulator, but a decent conductor of heat?

 

[LukeA]

come to think of it, isn't aluminum oxide an electrical insulator, but a decent conductor of heat?

HAIII is fairly poor at conducting heat compared to common heatsink metals such as metallic aluminum or copper.

Edit in bold.

 

[Tekno_Cowboy]

HAIII is fairly poor at conducting heat.

But it is an electrical insulator, right?

 

[LukeA]

But it is an electrical insulator, right?

It is.

 

[Tekno_Cowboy]

A sleeve would make sense then, if the light is anodized both inside and out. There would be no other way to connect negative and positive ends of the light.

 

[LukeA]

A sleeve would make sense then, if the light is anodized both inside and out. There would be no other way to connect negative and positive ends of the light.

The electricity would travel through the aluminum instead of the oxide, but brass offers some advantage, I guess.

 

[gadget_lover]

Some old plastic flashlight lights used the same trick. The plastic body did not conduct. They could have added a wire, arranged for it to be glued in place, added a contact ring, etc but it was sometimes cheaper and easier to just drop in an extruded brass tube. That way, it does not matter if it twists, and the body of the light becomes simply structural, not an electrical component.

Daniel

 

[Tekno_Cowboy]

The surefire nitrolon lights use a similar trick, with what appears to be aluminum.

 

[scott.cr]

I have a flashlight with a brass sleeve on the inside of the battery tube. The outside is HAIII. Can anyone tell me why a brass sleeve might be used?

I haven't seen this light in person, but is it possible it's a brass-colored chem film on the aluminum?

Most coatings used on aluminum appears gold/brass in color. Take a look at the inside of a Surefire.

 

[Tekno_Cowboy]

I haven't seen this light in person, but is it possible it's a brass-colored chem film on the aluminum?

Most coatings used on aluminum appears gold/brass in color. Take a look at the inside of a Surefire.

See post #4. Scratching also reveals brass. I have a Surefire 9P and G2. The 9P has a coating that changes the color, but you can still tell it's aluminum.