Well guys, I'm at it again. I had the xray gun go through my hard drive shells to determine composition, because when it comes to aluminum there are really only a few grades that pay much better than "common unsorted clean extrusions". Now, this blurb I've put together is really only for those of us who can produce a volume of 1,000 lbs or higher on a regular enough basis a large scrap yard will do business with you.
Every single powdercoated/anodized hard drive shell I tested turned out to be a 6061. New Note! Western Digital and Seagate SCSI drives and proprietary server hotswap drives turned out to be 343 cast aluminum or very nearly such. They are NOT cast but that is the alloy they use. Expect to be paid cast for these drives but you should not be paid "old cast" as they do not have oxidation or dirt. Also other drives with "heatsink" reliefs (very thick fins) that are not two piece were also 343 and ARE cast aluminum. Every uncoated shell, that is appearance of totally bare aluminum with obvious forging marks (looks like swirls around the pressure points of the die) are 5052. Server drives (two piece upper and lower forgings) were Aluminum 110. Hard drives shells are not cast, they are extrusions that are then forged into the shape of the hard drive base. The coatings should have no bearing on sell price because they end up as dross when smelted for extrusion.
My scrap yard will give me a 7 cent premium over clean aluminum extrusions for 6061 and 5052, properly separated. Likewise platters are made of extruded sheet 6061 which is die formed then surface machined prior to electro-vapor coating. The surface is so thin we could not detect it's composition with the xray gun. I am told the recovery on platters is less than 2 grams per 1,000 lbs of platters, this may or may not be true but I don't see anyone paying extra for them beyond aluminum cost.
The rings, (spacers) and the motor spindle are 6061-T6, an exceptionally hard and high silicon content alloy. I throw these in with the shells.
Heatsinks with anodizing are almost always 6061, AL/CU heatsinks are always 6063 and MOST intel based all aluminum heatsinks are 6063. Aftermarket Thermaltake heatsinks were some sort of blend alloy with a high copper content and read when scanned as cast (which has high copper content) but not 343. They are still within tolerance for 6063.
I certainly hope this helps those who get enough to grade the aluminum they sell. Factor in that each computer can have 18 ounces of 6061/6063 aluminum, that's a pretty good take over time.
An update. 12-27-15
Since I have seen thousands more hard drives and heatsinks I thought I would expand.
Hard Drive shells are "die cast" though this isn't correct, forged is the correct term but you cannot "forge" aluminum, and it's 343 or 6061 aluminum, there are no other engineering material standards I could find. What happens is a chunk of an aluminum, a billet is laid in a die, heated to whatever the specs are for the process then pressed at extreme tonnage into a die. When you see cheaper drives you will see they are in fact cast. Not that by looking on the long side of the drive. One side will have obvious flashing from two parts of a mold the other side will have rough breakage from casting overflow. Sometimes they are rough cast and then punched in a die, usually this is the hallmark of made in china... My experience thus far has been that the shell makes all the difference in longevity, why? Because in a hard drive 1/10,000th of an inch makes all the difference. And now you know.
Likewise I have seen only 6061 high silicon content aluminum in the platters and rings.
In heatsinks I have found so far that ALL bare aluminum extruded heatsinks are 6063 and anodized or coated heatsinks could be either 6061 or 6063. ALL copper/aluminum heatsinks use 6063 aluminum from my findings. It's been a while since we spot checked anything but there you have it.
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Originally Posted by HipoGear
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