Large ring tongue lug terminal manufacturer?

[shrtrnd]

I just picked-up a bag full of large (stud size) ring tongue lugs, made for probably a 8-gauge AWG wire. They're stamped 'RD705', with no company ID.
I was wondering if anyone is familiar with this part number and might know who made them.
Of particular interest to me, is that they are very light-weight. I think they're solid aluminum,
which I've never seen before. I was wondering if they have a special application.
When I was much younger, I worked as a residential electrician. At the time, to save money
contractors were wiring houses with aluminum wire, instead of copper.
There were a lot of fires later, because if you weren't extremely careful when you terminated
the wire on the copper buss-bar at the service entrance, the aluminum wire could vibrate from
the 60 Hz line input voltage, heat-up, and start the panel box on fire.
If these are special purpose lugs, I'd sure like to know about it.
Thanks

 

[GreenGiant]

They may be zinc or nickel alloyed copper, they tend to be lighter in color and weight than pure copper, they make the alloys to prevent corrosion, if you cut one through you may see more of a copper color and that may help.

 

[shrtrnd]

They're solid silver-colored, but I suppose they could be some kind of alloy.
(As opposed to plated copper).
I crimped one, and it folded with very little physical resistance to pressure.
(As opposed to the brute force I usually have to use to crimp a terminal lug this size)
I'll keep looking for info on them. I'm wondering if they're special, for a specific purpose.