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Message-ID: <202351.79217.qm@web111509.mail.gq1.yahoo.com>
Date: Sun, 18 Jul 2010 07:08:02 -0700 (PDT)
From: Tom Walter <roundrocktom@yahoo.com>
Subject: Re: [FlyRotary] Tie Down Hardpoints
To: tmann@n200lz.com
Cc: flyrotary@lancaironline.net
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Thomas,

No idea what plane you are building, but Cozy Girls had some plates made from 
aluminum and alodined. http://www.cozygirrrl.com/aircraftparts.htm

With threading, generally depth should be 1.5 times the bolt diameter -- for a 
steel bushing.  So 1/4" bolt, means a 3/8" steel bushing is fine. I like to go a 
little thicker with aluminum (you mentioned 28tpi which implies steel, as for 
aluminum I would use 20 tpi).  1/4" steel plate seems almost too heavy.  0.071" 
4130 plate with a welded in bushing would be fine.  Primer and painted and no 
rust worries (My fuselage is 4130 tubing).

Tom Walter