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RE: ASTM F 1852 "Twist Off" Bolts

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Generally, I do not require the manufacturer to visit the site and demonstrate the bolts.  The provisions of the RCSC Section 7 requires a "Pre-Installation Verification", but the manufacturer's rep does not have to be at the site, and I do not require it in my specifications. 
 
On large projects, I like to have a requirement that the bolts are re-verified if the bolts have not been tensioned prior to exposure to weather.  The lubricant used is often water soluble, and if the lubricant is not sufficient, the splines will snap prior to achieving the appropriate tension. 
 
For some other interesting aspects, I would suggest reading "INSTALLATION CHARACTERISTICS OF ASTM F1852 TWIST-OFF TYPE TENSION CONTROL STRUCTURAL BOLT/NUT/WASHER ASSEMBLIES", by Tan, MaleevBirkemoe from the University of Toronto. 
 
I have specified the use of DTI washers in addition to twist off bolts on projects to take advantage of the installation ease of the twist offs with the surety of the washers.  It was a rare project with a limited construction window and a lot of other difficulties.  And we did some testing in advance of the steel erection. 


Regards, Harold Sprague


 

To: seaint(--nospam--at)seaint.org
Subject: ASTM F 1852 "Twist Off" Bolts
From: canitzcf(--nospam--at)aol.com
Date: Fri, 22 Apr 2011 18:27:08 -0400

To all -
  For all of you who were SEORs for recent structural steel projects and required the "Twist Off" type bolts for the connections, did you require the TC assemblies manufacturer to visit the site and demonstrate installation of these bolts before steel erection could commence?
 
Doesn't the RCSC Structural Joints Specification pre-installation demonstration process by the inspector and erector suffice?
 
TIA,
Charlie Canitz, PE
Annapolis, MD