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RE: SAE J429 dimensions

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Paul,
My copy is a bit old, but SAE J429 covers "Mechanical and Material Requirements for Externally Threaded Fasteners".

The physical dimensions and tolerances are usually specified in ANSI B18.2.1. There are applications where we structural engineers see substitutions with J429 bolts. The telecommunications tower industry comes to mind. They were used in order to skirt the RCSSC installation requirements of A325 bolts and because the J429 bolts had full length threads and the RCSSC did not apply to J429. Currently you can spec an A 325 T bolt that also has full length threads. Pre-engineered metal buildings often use an A325 T.

The J429 8.2 bolt is a low carbon, martensite steel, fully killed, fine grain, quenched and tempered bolt. It has a tensile of 150 ksi, and a yield of 130 ksi.

Be careful with the SAE J429 bolts. Some years ago the foreign bolt stock was polluted with counterfeit bolts that were not the strength that was billed. You may want to require sending a percentage of bolts in for testing at at lab. As a minimum, run a given percentage of bolts to proof load in a Skidmore.

One of the unknown advantages of tensioning bolts is that if they do not meet specified strength, they will most likely break during tensioning. If you do not tension the bolts per the RCSSC A325 requirements, you should require additional testing as required in the SAE J429 to be submitted to guard against counterfeits.

Regards,
Harold Sprague





From: ad026(--nospam--at)hwcn.org (Paul Ransom)
Reply-To: <seaint(--nospam--at)seaint.org>
To: seaint(--nospam--at)seaint.org (SEAINT)
Subject: SAE J429 dimensions
Date: Tue, 24 Aug 2004 20:22:58 -0400

I don't have easy access to a copy of the spec. Does SAE J429 describe
flanged bolts and nuts (possibly with serrated face)? Or is this
physical aspect outside the spec?

I'm looking at a situation with Gr 8.2 bolts; not dynamically loaded;
does not have a  pre-tension requirement. I have been told that it is
simply an economy issue compared to A325 coated with washer.

I do not have an issue with the appication. I just want to confirm that
the bolt is what it is claimed to be.

--
Paul Ransom, P. Eng.
Civil/Structural/Project/International
Burlington, Ontario, Canada
<mailto:ad026(--nospam--at)hwcn.org> <http://www.hwcn.org/~ad026/civil.html>

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