[TowerTalk] FW: Silver vs Aluminum vs Copper Re: OT:

[jimlux]

On 3/4/19 10:51 AM, Jim Thomson wrote:
> Date: Sun, 3 Mar 2019 22:47:53 -0600
> From: "Matt" <maflukey at gmail.com>
> 
> Subject: Re: [TowerTalk] FW: Silver vs Aluminum vs Copper Re: OT:
> Inductor Calculator
> 
> <Look for 18-8 or 300 series stainless steel.   The 18 means 18% chromium and the 8 means 8% nickel.
> 
> <73
> 
> <Matt
> 
> <KM5VI
> 
> ##  18-8  can still be found, but for the most part, the 18-8  has been replaced by the 3XX  series of SS.
> 304 SS  is  super shiny,  excellent corrosion resistance, and   readily available.   316  SS  is marine grade,
> and is supposed to be the ultimate in corrosion resistance for harsh  environments.. like salt spray, acid rain etc.

302 seems to be similar to 18-8 - 16-18 Cr, 8-10 Ni, ultimate tensile 
100kpsi
304 is 18-20 Cr, 8-10.5 Ni, so more chromium, - ultimate strength is 95 
kpsi  - this is probably closest to 18/8 or 18/10

316 is more easily weldable.   16-18% Cr, 10-14 Ni, so it's higher in 
nickel than 18-8, which is probably why it's magnetic. 90 kpsi ultimate. 
  More Molybdenum so it's corrosion resistance is better.





> 
> ##  as far as strength,  SS  is not strong material, it has the same tensile strength as  grade 2 mild steel, but plenty
> good enough for most applications.  Phosphor bronze is a bit stronger, but our local suppliers  dont usually carry it.
> However  Phosphor bronze  is readily available online.    I have also  silver plated  phosphor bronze  with the ..cool amp
> goop....and ditto with   brass..and also copper.   IMO,  silver plated  phosphor bronze is about as good as it gets.
>    Phosphor bronze is all I see being used by various HF  SW  Broadcast  ant  suppliers,  so they must be onto something.
> 
> 

For corrosion resistance, I imagine.. most phosphor bronze alloys are 
pretty resistive
from "copper.org"
The most widely used phosphor bronze contains 0.2% phosphorous and 5% 
tin; It has only half the conductivity of its most popular brass cousin, 
copper-30% zinc (15% IACS vs. 28% IACS). Unlike the brasses, which have 
a rather wide range of electrical conductivity (28-56% IACS), most 
phosphor bronzes range from only 11 up to 20% IACS , although there are 
exceptions with higher conductivity.