[TowerTalk] Cushcraft Parts From MFJ

[Charlie Gallo]

On 11/25/2010 Jim Thomson wrote:



> ##  My guess is, instead of using  6061-T6  or  6063-T832,  they have  gone
> to a cheap alloy, like  3003,  which comes in various grades of hardness, listed
> as  H-0  to H-14.    H-0   is only 6 ksi yield, and the  strongest is no match  for
> 6061-T6  or  6063-T832.   

What is interesting is "yield strength" vs ultimate strength - various tempers WILL have different yield strengths - "Yield strength" is the amount of force to cause the material to BEND and NOT return to it's original shape - "Ultimate strength" is the amount of force needed to BREAK the material

Now, IF the alloy is actually the same (hint, a lot of the Al that is sold is NOT the same for the different tempers, and some can't be tempered after alloying) - the "Ultimate strength" doesn't change - Note however, the Alcoa data sheets DO tend to guarantee a higher ultimate strength for higher tempers (not all - lets talk 6061 - they  guarantee the same minimum for T0 and T4 - and of course T6 and T6511 are the same - in fact I often see t651(1) sub'd for T6)

I know you take say a piece of 0-1 steel - the ultimate strength is totally unchanged by hardening - what IS strange - say you go just under yield strength - the hardened steel will flex a LOT less that the unhardened, and still return, but they break at the same point

If I see my wife's uncle this holiday season, I'll ask him to write something up - he's a (now retired) PhD in materials science who specializes in Alloys (mostly Fe Alloys), and is considered one of the top guys in the field (as in international award winning)

-- 
73 de KG2V - Charles Gallo
Quality Custom Machine-shop work for the radio amateur (sm)