Return to index: [Subject] [Thread] [Date] [Author]

RE: Bent anchor bolts / welding high strength bolts?

[Subject Prev][Subject Next][Thread Prev][Thread Next]
If I understand it correctly, the quenching process involves heating the
metal evenly to a specified high temperature (we used to use color as an
indicator in metal shop, glowing cherry red, white hot etc.) then plunging
into a cold bath of water or oil (or something else?...).  The tempering
process is then applied whereby the metal is reheated a new specified lower
temperature and then slowly cooled which allows the metal to retain strength
without having a lot of the residual stresses created by the quenching
process.

I doubt that this can be achieved for a threaded rod or bolt as there would
be little way to evenly heat then rapidly quench all parts let alone temper
it.

Nicholas Blackburn

-----Original Message-----
From: Balmer James [mailto:James.Balmer(--nospam--at)rsandh.com]
Sent: Wednesday, June 27, 2001 2:23 AM
To: 'seaint(--nospam--at)seaint.org'
Subject: RE: Bent anchor bolts / welding high strength bolts?


In the ASD manual, page 4-4, there is a statement "Anchor bolt material that
is quenched and tempered (QT) should not be welded or heated."  Is there an
established procedure for field welding a high strength (QT)anchor bolt and
then repeating the quenching and tempering process to regain the high
strength lost in the welding process?

James Balmer

-----Original Message-----
From: desi.kiss(--nospam--at)wgint.com [mailto:desi.kiss(--nospam--at)wgint.com]
Sent: Tuesday, June 26, 2001 5:52 PM
To: seaint(--nospam--at)seaint.org
Subject: RE: Bent anchor bolts


Bending back bolts is a bad practice, although possible in
some instances.
A 36 small bolt diameters if carefully preheated, and the column carries
no moment.
For high strength bolts it is a more difficult situation.  By bending back
bolts
the structural integrity is damaged, and they also may fail in  rupture.
Welding then may be required and that is completely a different issue.

Desi J. Kiss
Washington Group International
Irvine, CA 92614



-----Original Message-----
From: Scott Maxwell [mailto:smaxwell(--nospam--at)engin.umich.edu]
Sent: Tuesday, June 26, 2001 12:35 PM
To: seaint(--nospam--at)seaint.org
Subject: Bent anchor bolts


I have a question that was asked of me and I could not locate a solid
answer anywhere.  I figure someone here will know...

Say you have an anchor bolt (opps, that would be anchor rods...damn, keep
forgetting that) sitting there out in the field prior to the column being
placed and it is just minding its own business, when "Wham!" someone runs
into it and bends it.  Someone asked if there is anything in a code
document that would prevent that anchor rod from being cold bent back
straight.  If there is nothing in code form, any personal opinions on cold
bending it back straight?

Thanks,

Scott
Ypsilanti, MI



******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
* 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ********