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RE: general bolt questions

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Mark,

I am used to typically using 3/4" bolts.  I have, however, used 1"
diameter bolts.  The only recommendation that I offer is that you either
use all one size on a job or if using multiple sizes, don't use sizes
within 1/8" of either (i.e. don't use 3/4" and 7/8" on the same job).
Bolts that are within 1/8" of each other in the diameter can be confused
with each other and potentially installed at the wrong location.  It is
much more difficult to confuse a 3/4" and a 1" diameter bolt.

With regard to the edges distances, I can't give a "solid" answer since my
steel books are at home (I am now at a primarily concrete oriented job,
and haven't bothered to bring in my steel books...yet), but I can
speculate.  Minimum edge distance is a function of bolt diameter and edge
condition (i.e. is it a sheared or rolled edge).  It is possible that the
example in the connections manual is "assuming" a rolled edge (rolled
edges require a small minimum edge distance if my memory serves me
correctly).

Hope that helps,

Scott


> 
>  -----Original Message-----
> From: 	Mark Pemberton [mailto:Markp(--nospam--at)lbdg.com] 
> Sent:	Thursday, February 08, 2001 3:03 PM
> To:	'seaint(--nospam--at)seaint.org'
> Subject:	general bolt questions
> 
> We typically use 3/4" diameter bolts for beam to column and
> beam to beam connections, but are considering going to 1"
> diameter bolts.  What is the typical industry standard?
> We have also noticed an inconsistency within the AISC LRFD
> manual (2nd addition) for the top and bottom minimum edge
> distance for bolts at a shear tab.  Table J3.4 requires for 1"
> diameter bolt, 1-3/4" edge distance for a sheared tab while
> figure 9-15 of Vol 2 (the connections manual) shows an allowable
> 1-1/2" edge distance.  How is this typically resolved?
> 
> Mark Pemberton, P.E.
> Lionakis Beaumont Design Group
> 
>