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RE: Welding Run-Off Tabs...

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Unfortunately, the surface roughness values were changing near the end of
the project, and the reference to the AWS surface roughness gage ended up
incorrect. I'll take credit for not catching the error. Sample 3 is 1000
microinch. Sample 2 is 2000 microinch. 500 microinch is sample 4, not sample
3 as indicated in FEMA 353. Reference is to AWS C4.1-77, a plastic sample
that's been around a long time.

For some additional clarity, see AWS D1.1, section 5.15.4.3. No reference is
made there to sample 4, however.

There are some surface roughness gauges available in a variety of
roughnesses, and in a variety of prices. McMaster's has a ancient plastic
template, with accompanying ancient text, that sells for about $50.00, but
at least it is clearly labeled.

This (sample 4, not 3) should be appearing in errata, whenever that is
assembled.

Bob Shaw
Steel Structures Tech Center
www.steelstructures.com

-----Original Message-----
From: Ben Faircloth [mailto:benfair1(--nospam--at)home.com]
Sent: Wednesday, November 15, 2000 7:05 PM
To: seaint(--nospam--at)seaint.org
Subject: Welding Run-Off Tabs...



The new FEMA 353 Document requires that weld run-off tabs be removed(from
outboard of a beam flange for instance), and that the surface be finished to
500 micro inches.  AWS D1.1 requires that these surface types meet their
"SAMPLE 3" finish where;
Sample 4 = smoothest
Sample 1 = roughest

The steel fabricator has sent to my attention a "widget" from AWS that shows
examples of each roughness (SAMPLE 1-4).  The steel fabricator has told me
that they are finishing all of the surfaces from which weld run-off tabs
have been removed to "SAMPLE 3".

Can anyone help me bridge the gap between "SAMPLE 3" and 500 micro inches?
I expect that at some level "SAMPLE 3" has to be objectively defined(500
micro inches or something along those lines).

Thank you for you help,
Ben Faircloth