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RE: High-strength bolts

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I always get nervous when engineers say torqued in lieu of tensioned, but
that is another issue.  

If the bolts were not tensioned, you do NOT have friction bolts.  

An A325 bolt used in a friction connection, bearing, or an "X" type bearing
connection is physically all the same bolt.  To be a true friction (slip
critical) connection, the bolts MUST be tensioned and the faying surface
condition must be controlled to a degree.  The only thing that makes an X
type of bearing connection or an N type of bearing condition is whether or
not the threads are in the shear plane or not.  Generally even if you
specify a regular bearing bolt, you will get an "X" type of bearing bolt
because of the grip and nature of the plies.  You are more prone to get an X
type of bolt if washers were used.

If A325-X bolts were specified, obviously the intent was to allow for a
certain degree of slip in the connection.  This is not normally acceptable
for moment resisting connections.  Generally moment frames are made with
slip critical (friction) connections.  You should be able to check the shop
drawings to see if the threads will be in the shearing plane.  

Harold Sprague

> -----Original Message-----
> From:	SMEZSEZ(--nospam--at) [SMTP:SMEZSEZ(--nospam--at)]
> Sent:	Friday, April 21, 2000 3:59 PM
> To:	SEAINT(--nospam--at)
> Subject:	High-strength bolts
> A325-X bolts were specified to be installed at steel to column moment 
> resisting connection in an OMRF.  Instead, A325  friction type bolts were 
> installed, but were not torqued., but tightened well.  The bolts are 
> presently inaccessible.  Will the friction type bolts be accectable
> without 
> having to be torqued.  
> Thank you, 
> S. Mezey