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Galvanized TC Bolts

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Ken,

We just completed a major power plant project using all galvanized twist
off bolts.  We had no problem with them sticking in the wrench however we
had several other issues.  The first was procurement.  Apparently the only
manufacturer that galvanizes their own bolts is LeJeune and the larger
diameters have a long lead time.  Note that ASTM F1852 requires that this
be "Mechanically Galvanized" as opposed to Hot Dip Galvanized.  Other
suppliers buy their bolts from Nucor, Lincoln, Haydon, etc. and have them
galvanized by a third party which can create a liability issue if something
goes wrong.  During our initial pre-installation testing none of our
LeJeune supplied bolts passed.  After a long investigation we found that
the nuts either had no lubrication or according to the manufacturer they
had the wrong type of lubrication.  Currently if you buy galvanized bolts
from LeJeune the nut should be almost jet black.  This indicates that it
has been dipped in their special "proprietary" lubricant.  Our second issue
was the detailer needs to provide greater wrench clearance for TC bolts.
The power tools required are larger than the ones used on regular A325
bolts.  See AISC Table 8-5, "Entering and Tightening Clearances,
Tension-Control ASTM A325 and A490 Bolts".  We had to special order some
extra long extensions because of some very tight clearances.  One last
issue is that I assume you are using galvanized bolts for an outside
application so after the TC bolt is twisted off you have a bare end that
will need to be painted with a zinc rich paint.

Thomas Hunt, S.E.
Duke/Fluor Daniel

----- Forwarded by Tom Hunt/DFD on 10/31/01 07:00 AM -----
                                                                                                                   
                    "Ken Peoples"                                                                                  
                    <kspeoples@lvt       To:     "Seaint" <seaint(--nospam--at)seaint.org>                                      
                    a.net>               cc:                                                                       
                                         Subject:     galvanized TC bolts                                          
                    10/31/01 05:43                                                                                 
                    AM                                                                                             
                    Please respond                                                                                 
                    to seaint                                                                                      
                                                                                                                   
                                                                                                                   




I heard recently that it is not good to specify galvanized TC bolts because
the galvanized pieces that twist off get stuck in the "wrench" and cause
major delays in extracting.  Have any of you experienced this?
Thanks,
Ken

Kenneth S. Peoples, P. E.
Lehigh Valley Technical Associates
1584 Weaversville Road
Northampton, PA 18067-9039
Phone: (610) 262-6345
Fax: (610) 262-8188
e-mail: kpeoples(--nospam--at)lvta.net



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