To: "SEAOC Newsletter" <seaint(--nospam--at)seaint.org>
Subject: Re: ASD Design of Threaded Fasteners
From: Christopher Wright <chrisw(--nospam--at)skypoint.com>
Date: Tue, 30 Jan 01 16:42:59 -0600
>Why is the Tensile Stress area larger than the Min. Root area for threaded
>fasteners? (See pg 4-147 of ASD 9th Edition)
>Shouldn't I be using the smallest cross section for my design?
The allowable stress for a fastener is based on the tensile stress area
figured as shown on the screw thread data table. This relationship comes
from some detailed work by the NBS and does in fact represent the failure
mechanism in tension. Read through ASTM A325 for some background.
Christopher Wright P.E. |"They couldn't hit an elephant from
chrisw(--nospam--at)skypoint.com | this distance" (last words of Gen.
___________________________| John Sedgwick, Spotsylvania 1864)