[Amps] brass or BNP hardware

[John Lyles]

In RF power amplifiers, HF to VHF range, I have used brass or nonmagnetic stainless steel hardware for years, after having been "Burned" by steel screws - pun intended. Several times in my career
I have seen bolts turned black and tarnished from RF heating this way. If RF current can flow in the steel, then it can make eddy currrent losses and heat up. However, if it is not carrying current, not a problem. 
The reason I try to stick with brass or SS is that later on, someone is working on the product, cannot remember why this special screw is only in this hole and that. So by making it all one type, when inside the RF compartment, you 
make service, repair and spare parts inventory simpler. These simple policies are carried on in my mind when starting new amplifiers. 
73
John 
K5PRO