<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
          <<  Lancair Builders' Mail List  >>
          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
>>
The heat treatment of steel and aluminum is almost the opposite. Steel is
heated to a high and some temp. then rapidly cooled, which makes it very
hard. Steel is then heat soaked at a relatively high temperature (tempered)
which softens it to the desired temperature. Aluminum alloys are heated
to a high, but much lower temperature and cooled rapidly, which makes them
soft and the heat treateable ones are heat soaked at a relatively low temp.
(100 - 160 c) which hardens them. There is a somewhat abreviated explanation
in the AS catalog.

That gear leg is probably made of 7075 whith a bunch of letters after it. I
wouldn't heat the gear legs to 400 F for 20 min. without asking the
manufactuer, who did the original heat treatment.

Bill N7WB


[Bill, the gear legs are made of 4130 steel, not 7075 AL.     <Marv>   ]

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
LML website:   http://www.olsusa.com/Users/Mkaye/maillist.html
LML Builders' Bookstore:   http://www.buildersbooks.com/lancair

Please send your photos and drawings to marvkaye@olsusa.com.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>