Date:         Tue, 21 Oct 2003 22:10:42 -0700
Reply-To:     Doktor Tim <doktortim@ROCKISLAND.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Doktor Tim <doktortim@ROCKISLAND.COM>
Subject:      Re: sheer bolts/steering column
Comments: To: THX0001@AOL.COM
In-Reply-To:  <150.259a6925.2cc76449@aol.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 09:40 PM 10/21/2003, you wrote:
>.  I think the best explanation for using shear
>head bolts is that they provide a sure and certain minimal torque when they
>are fastened and, perhaps more importantly in an assembly line environment, an
>accurate way of checking that these vital fasteners have been installed per
>spec.

No, I'm sorry, but they are called shear bolts because they are designed to
shear in a collision. Look over that design closely and you will see that
in a frontal impact when your chest hits the wheel and the bolts shear, the
steering column will just slip apart and you will break less ribs.  They
have break off heads because if they put a standard head on them they would
be shear upon install by everyone who doesn't know the difference, and they
don't want just any yahoo with a Chinese wrench to be able to remove them
in the first place. As well, the metal is so soft that you would round off
the corners of a standard hex head by just breathing on it. I am sure
marketing hated the cost of those special bolts, but the lawyers made sure
the engineers were allowed to do this one right regardless.