X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 06 Oct 2006 23:17:07 -0400 Message-ID: X-Original-Return-Path: Received: from web34912.mail.mud.yahoo.com ([209.191.68.191] verified) by logan.com (CommuniGate Pro SMTP 5.1c.5) with SMTP id 1445134 for lml@lancaironline.net; Fri, 06 Oct 2006 00:10:24 -0400 Received-SPF: none receiver=logan.com; client-ip=209.191.68.191; envelope-from=n103md@yahoo.com Received: (qmail 47333 invoked by uid 60001); 6 Oct 2006 04:10:02 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:Received:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=3hHCBUQBBikTnfM6JvfUuMIuhdg5I7vxElK6X4BZtGSI1lCtCZsZUbx3SvG6NxMyafJ0AxePL2bqxqXqw5ih0qkh4v9QIDKdH1NsbBjLOtC5c5ldbMfxW/OXdhzGvgiT6mKpu1OJwCYUVxoDWZuVt4ihlw5s0hpWaLOKmJ/g5o8= ; X-Original-Message-ID: <20061006041002.47331.qmail@web34912.mail.mud.yahoo.com> Received: from [12.146.139.19] by web34912.mail.mud.yahoo.com via HTTP; Thu, 05 Oct 2006 21:10:02 PDT X-Original-Date: Thu, 5 Oct 2006 21:10:02 -0700 (PDT) From: bob mackey Subject: Re: torque specs X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-712100999-1160107802=:37108" Content-Transfer-Encoding: 8bit --0-712100999-1160107802=:37108 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit > The recent discussions about proper torque on such things as engine mount > bolts reminds me that over the years I have heard from several normally reliable > sources that using a torque wrench on locking nuts (either plastic or all metal) is > not only a waste of time but possibly even a bad idea. ... > In other words, if the torque is really important don't use lock nuts. > I am curious what others on the list might have to say about this. Locknuts are highly overrated. Lockwashers are just as bad or worse. If a threaded fastener is properly sized for the job, and sufficiently preloaded or stretched (regardless of the "torque", then it won't vibrate loose. I highly recommend buying and reading "Nuts Bolts and Fasteners" by Carrol Smith. http://www.amazon.com/Fasteners-Plumbing-Handbook-Motorbooks-Workshop/dp/0879384069 It is written by a race car builder who isn't afraid to name names and tell it like it is. There's good engineering explanations, and much about the proper way to use a bolt or nut. Keep in mind that race car builders use most of the same construction techniques as airplane builders, but stress the components much closer to the limits. Race cars have much more vibration and more moving parts and attract some of the best engineering talent. There is much to learn from those guys. -bob --------------------------------- Do you Yahoo!? Get on board. You're invited to try the new Yahoo! Mail. --0-712100999-1160107802=:37108 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: 8bit > The recent discussions about proper torque on such things as engine mount
> bolts reminds me that over the years I have heard from several normally reliable
> sources that using a torque wrench on locking nuts (either plastic or all metal) is
> not only a waste of time but possibly even a bad idea. 
...
>  In other words, if the torque is really important don't use lock nuts. 
> I am curious what others on the list might have to say about this.

Locknuts are highly overrated. Lockwashers are just as bad or worse.
If a threaded fastener is properly sized for the job, and sufficiently
preloaded or stretched (regardless of the "torque", then it won't vibrate loose.

I highly recommend buying and reading "Nuts Bolts and Fasteners"
by Carrol Smith.
http://www.amazon.com/Fasteners-Plumbing-Handbook-Motorbooks-Workshop/dp/0879384069
It is written by a race car builder who isn't afraid to name names and
tell it like it is. There's good engineering explanations, and much about
the proper way to use a bolt or nut. Keep in mind that race car builders
use most of the same construction techniques as airplane builders,
but stress the components much closer to the limits. Race cars have
much more vibration and more moving parts and attract some of the
best engineering talent. There is much to learn from those guys.

-bob

Do you Yahoo!?
Get on board. You're invited to try the new Yahoo! Mail. --0-712100999-1160107802=:37108--