On 03.6.7 11:14 PM, "Bruce Rubenstein" <[EMAIL PROTECTED]> wrote:
> Referring to a metal as aluminum is about as meaningful as saying it's > made of "stuff". Things are made from aluminum alloys. I already said somewhere that it must be alloy but for the purpose of the discussion in this list, referring to aluminum is good enough. I had no intention to go deeper than that. It is futile. We were talking about Aluminum, steel and brass etc in a general term. > Some alloys have to be treated after machining to attain their proper > characteristics (Aircraft alloys like T4 and T6). You obviously do not know the aircraft aluminum which is used for wing span and landing gear etc. You say "treated" or "proper characteristic" etc ina very general terms but they are NOT 'treated" for proper "characteristics". T series aluminum are forged, and post machining treatment of the forged material is usually for stress relief. But not let's not go deeper than this. It has nothing to do with the lens barreol argument here. Let's just say that the lens barrel is NOT a T series forged aluminum for sure. End of story. Ken
