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RE: Shear-off bolted connection

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Any method of installation requires special inspection.  The ICBO structural
steel special inspection certification program is about the best for
covering bolting and welding.  A good compromise might be to use DTI washers
on 10% of the twist off bolts, and use hex head twist off bolts.  The
installation method should still be verified with a direct tension
calibration device (Skidmore) on the project site.

Harold Sprague
The Neenan Company

-----Original Message-----
From: Maria I. Falconi [mailto:maisabel(--nospam--at)]
Sent: Friday, January 15, 1999 10:12 PM
To: seaint(--nospam--at)
Subject: RE: Shear-off bolted connection

Dear All,

Thanks for all the responses.  I was intrigued by these DTI's, and found a
web page on them- and based on the stuff they're
saying, DTI tensioning is good and the other types are awful (DTI's are
given a 100-120% tightening range whilst twist-offs are given 0-100% ???).

Maybe we can elaborate a bit more on these two types of bolt tensioning.
Now I'm worried that the twist-offs aren't reliable enough.  Is the
twist-off good enough?  Is the DTI lots better?  Or are they both just as

Maria Falconi

-----Mensaje original-----
De: Harold Sprague <harold.sprague(--nospam--at)>
Para: 'seaint(--nospam--at)' <seaint(--nospam--at)>
Fecha: Jueves 14 de Enero de 1999 06:44 PM
Asunto: RE: Shear-off bolted connection

>I don't know for sure, but I believe that Bethlehem does not make the bolts
>any more. But I believe that Ingersol Rand still makes the tool as do other
>tool manufacturers. It's been awhile since I installed them, but I believe
>that the twist off bolt is universal and will fit any of the installation
>Another manufacturer is T. S. Bolts and Tools by the Bristol Machine Co. in
>Walnut, California 800-798-9321.
>On another thread I noticed the DTI load indicating washer. It too is a
>good product, but the iron workers prefer the twist offs because:
> 1. The LeJeune gun is electric not pneumatic. No long air hose or
>compressor. The electric gun is lighter and the chord is lighter.
> 2. The LeJeune gun is not an impact tool and can be handled with one
> 3. You can see if the bolt is tight by long distance observation.
>The structural engineers generally prefer the DTI's because of the
>perception that if in the process of tightening a bolt group, a bolt is
>relieved of tension, it can be seen in the gap. That perception may not be
>accurate. The deformation in the dimples of the DTI is a plastic
>deformation. That is the reason you can not reuse them.
>In any bolt "tensioning" process, the bolts in the entire group must be
>brought to snug tight prior to final tensioning. Proper tensioning requires
>special inspection to confirm the process.
>Harold Sprague, P.E.
>The Neenan Company
>harold.sprague <mailto:harold.sprague(--nospam--at)>
>-----Original Message-----
>From: Robert Rollo [mailto:rrollo(--nospam--at)]
>Sent: Thursday, January 14, 1999 11:45 AM
>To: 'seaint(--nospam--at)'
>Subject: RE: Shear-off bolted connection
>does bethlehem still mfr the LIB system, with the ingersol rand tool ?
>are they compatible ?
> -----Original Message-----
>From: Harold Sprague [SMTP:harold.sprague(--nospam--at)]
>Sent: Thursday, January 14, 1999 12:40 PM
>To: 'seaint(--nospam--at)'
>Subject: RE: Shear-off bolted connection
> Contact the LeJeune Bolt Co. in Minnesota @ 800-872-2658. They
>handle the
>bolts and the installation tools.
>Harold Sprague, P.E.
>The Neenan Company
>harold.sprague(--nospam--at) < mailto:harold.sprague(--nospam--at)
><mailto:harold.sprague(--nospam--at)> >
> -----Original Message-----
>From: Maria I. Falconi [ mailto:maisabel(--nospam--at)
><mailto:maisabel(--nospam--at)> ]
>Sent: Thursday, January 14, 1999 11:56 AM
>To: seaint(--nospam--at)
>Subject: Shear-off bolted connection
> Dear Colleagues,
> I need to find information about a type of bolted construction that
>involves bolts that have a spigot at the end of the thread which shears off
>at tightening when the required torque is reached.
> Special power drivers are used to install bolts in this fashion. I need
>to find out about purchasing and/or renting these machines.
> I got a hold of a brochure from RTB Tooling (Rapid Tension Bolts) which
>talks about these tools but I don't have enough information (no phone
>number, etc).
> The description of how the RTB works is as follows:
>"After the connection is fitted, the outer socket of the tool applies a
>clockwise rotational force to the nut as the inner socket applies a counter
>clockwise force to the spline. When the fastener exceeds the required
>tension, the spline end will shear".
> I would greatly appreciate any information on where to get a hold of
>suppliers of this type of equipment, in the States or in South America. I'm
>looking at erecting a 10-story steel building with this system (1200 tonnes
>of steel involved) and I urgently need to price the purchase or lease of 13
>of these power drivers.
>Maria I. Falconi
>Guayaquil, Ecuador
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