[R-390] R390 Gear Chemistry

[Glenn Scott]

Thanks Bob and Charles.. 


Not being a chemist, I didn't know what the composition was but I have heard those gears called brass and bronze interchangeably for decades;  I was just curious based on my experiences with brass.
The info Charles gave regarding the material may be 360-Brass seems to be a good choice/answer. I did some reading from a google search and found the following link and this seems like the best description of what  those gear actually be made of.


https://www.speedymetals.com/information/material13.html


My experience over the years with brass has been, it's somewhat soft and I questioned its use as a gear, especially, in receivers that have survived well after 5 decades. My brass experience was obviously using a different alloy of Cu and Zn. And perhaps the slight attraction to a Neodymium magnet was possibly due to the fraction of 1% of Fe. Since brass can be alloyed numerous ways, Bob's comments were also VERY helpful.. 


Not that anyone probably cares too much, but perhaps someone should make a note in the Pearls Of Wisdom Files regarding 360-Brass. Perhaps some other future R390A and/or (Non A) enthusiast may be curious.  Maybe that same alloy was used in the 75A, 51J and R388 series receivers as well.


One thing that's great about this list is, generally, any reasonable question sent up the proverbial Flagpole is usually met with kind, competent, knowledge and or experiences from many of the exceptionally bright people who frequent here.


Thanks and 73,


Glenn Scott WA4AOS
DSM Labs
864 684 2956