In a PM conversation with another member who will post his experiences and my own lightly banging a Romisen RC G2 with the stainless steel bezel of a cyclone i have discovered that the aluminium in many of our lights is not that the top of the line (though it seems to be definitely adequate)
I am curious what they do to it to make it cheaper (i know a little bit about aluminium in general, and i’ve read about 6061 and 7075 in the past) and how the debasing of it influences its thermal conductivity and mechanical properties
I was the one discussing the Aluminum in different lights. What I do not understand is why all of the Chinese lights I have worked on are so soft. They ding and chip very easily. Also, when I mod them and polish them, they don't polish well. The metal seems "grainy", for lack of a better word. It does not smooth, but stays rougher, like it's too soft for it to be smoothed, even with the finest papers and steel wool.
When I polish a Maglite, I can get a mirror finish on it, but I can never do that with any Chinese light I have ever worked with.
What's the difference? Inferior materials or inferior processes?
This thread reminds me of the thread about the C303, which uses a harder alloy than other torches.
Is it worth measuring the resistance down a flashlight body ?
Without a traceable designation of heat or finish treatment, you can assume that the budget light manufacturers are using the material that is the easiest to machine, and likely the cheapest.
On the Practical Machinist forum, the general complaint of Chinese aluminum is that it is gummy and of inconsistent quality.
No mill marks? You're gambling with the composition of the metal.
Old Lumens had managed to polish Nightcore EA8 to a high gloss. Maybe reputable manufacturers like Olight, Fenix, Jetbeam or Foursevens uses higher grade materials?
Aluminum comes in many different grades , and compositions depending on many variables ..
First thing would be price , why would you use high grade alloy in a cheap light ?
Second would be , most lights are anodized , so most folks dont care as long as the surface finish wears well , and the body is not soft like butter ..
So , minimum cost and minimum quality to get the job done ..
If you are going into combat where your jumping in and out of ditches etc , and your light needs to put up with combat conditions , then a high grade aviation alloy is most likely desirable and worth the money , on the other hand if your light is going to spend most of its time on the night stand with the odd stint in the pocket of a robe , then maybe you dont need a $200 flashlight built to handle combat .. Well , you may want one , and you may even own one , and as for need ( who cares )
But bottom line is , stuff is built to price ..
Dont expect anyone to use a $25 billet of high grade alloy to make a $20 flashlight ?
Think more along the lines of 50c to a dollar worth of alloy ...
i understand using cheaper metal, but i want to know what i am actually buying, if i am told upfront that your selling me low quality metal then i have enough information to decide if the lower quality will meet my needs, otherwise you are selling to me under false pretenses (i can’t think of many customers who would appreciate being misled)
They are several temper grades to 6061 which cost more money for temper and make it stronger. I assume they use what ever is the cheapest alloy that’s considered 6061 and the cheapest strength grade (no temper).
6061 is a precipitation hardeningaluminium alloy, containing magnesium and silicon as its major alloying elements. Originally called "Alloy 61S," it was developed in 1935.[1] It has good mechanical properties and exhibits good weldability. It is one of the most common alloys of aluminium for general purpose use.
It is commonly available in pre-tempered grades such as 6061-O (annealed) and tempered grades such as 6061-T6 (solutionized and artificially aged) and 6061-T651 (solutionized, stress-relieved stretched and artificially aged).
+ There are some seriously better alloys out there now ...
And 6061 annealed being probably the cheapest and easiest to machine. That would also save on tooling cost. Less tooling wear. 6061-T6 has almost 3 times the strength of annealed 6061. You can definitely tell the difference when machining.
Most of my rocket motors use 6061-T6 for the casing. It is strong, but more importantly, if the motor over-pressureizes it stretches and splits instead of fragmenting into shrapnel. Something to remember when using WankerFire batteries…