Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: Bay Bridge Broken Bolts

[Subject Prev][Subject Next][Thread Prev][Thread Next]
That is a bit odd.  If the A 490 bolts are tensioned per the RCSC, the 
stress remains static until you exceed the tensioning force.  That should 
never happen.  If the issue is hot dipped galvanized, I don't blame them 
for not allowing them.  Hydrogen embrittlement is not well understood.

Regards, Harold Sprague

> Date: Mon, 13 May 2013 08:02:14 -0400
> From: design(--nospam--at)
> Subject: Re: [SEAINT-SEAOSC] Bay Bridge Broken Bolts
> To: seaint-seaosc(--nospam--at)
> Back in the 1970's, we were supplying steel to the New York Transit
> Authority and they would not allow A490 bolts in any dynamically loaded
> structures. This occurred again in the 1980's on a bridge for Rochester,
> NY. I don't know if these restrictions are still being applied.
> Gary
> On 2013/05/11 6:06 PM, Bill Polhemus wrote:
>> On 5/11/2013 4:27 PM, Harold Sprague wrote:
>>> The bolts specified were ASTM A354 BD, hot dipped galvanized.
>> Just interested: Why not use A490, assuming these are all for structural
>> steel connections? I'm no expert in this but I seem to recall that A490
>> is equivalent in strength to A354 BD but has more stringent quality
>> control requirements. Surely they would be more readily available and
>> less expensive than some sort of proprietary alloy.

Post your message to the list by sending it to: 

The email messages sent to the list will be saved in an archive on the World Wide Web.
These archives are located at:

To contact the list owner, send your message to:

Sponsored By: Pacific Structural & Forensic Engineers Group, Inc. (PSFEG)

To unsubscribe, switch to/from digest, get on/off vacation, or change your email address, click here.