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All,
Here's the reply from a bolts and nuts manufacturer's engineer to my
question regarding loss of tensile strength in used bolts. I went into
shis mainly because we don't have much choice about reusing fastener's
in our LBCs.
CR
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Date: Wed, 18 Oct 2000 21:02:04 +0100
To: Charles Robinson <ccrobins@ktc.com>
From Bill Eccles <bill at boltscience.com>
Subject: Re: Ask a question of Bolt Science
References: <E13lqAQ-0003Fb-00@uk-0.www.demon.net>
Charles,
Thanks for sending us a question via our 'Ask a Question' feature on our
website.
If the stress is below yield there will be no loss of strength of the
bolt. In fact on the second application the preload may well be higher
because generally the friction lowers slightly on subsequent
applications resulting in a higher preload for a given torque.
Sorry for the delay in answering your email.
I hope that this helps.
If you need any further clarification on the above or other information
related to bolted joints, please do not hesitate to contact me.
Best regards
Bill Eccles
Bolt Science - Providing expertise in Bolted Joint Technology
Visit our website at www.boltscience.com
Telephone +44 (0)961 300952 Fax +44 (0)1257 411650
In message <E13lqAQ-0003Fb-00@uk-0.www.demon.net>, Charles Robinson
<ccrobins@ktc.com> writes
>Below is the result of your feedback form. It was submitted by
>Charles Robinson (ccrobins@ktc.com) on Wednesday, October 18, 2000 at 10:09:50
>---------------------------------------------------------------------------
>
>company: Computer Helpers
>
>question: If a bolt is tightened to a specified torque such that it
>is stretched to a point below yield, then loosened and
>retightened to the same specified torque, will the bolt's
>preload be lower on the second iteration due to a loss of
>tensile strength in the bolt?
>
>---------------------------------------------------------------------------
>
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