Folks,
As Brian said, there are composition specifications for alloys in
compilations like the Unified Numbering System for Alloys
(UNS). Much in the way of metals compositional analysis is under the
auspices of ASTM International Committee E01 on Analytical Chemistry
of Metals, Ores and Related Materials. Therefore, there are standard
test methods that apply to most alloys. They may use XRF,
Inductively Coupled Plasma Optical Emission Spectrometry (ICPOES),
classical methods, Spark Source Atomic Emission Spectrometry (SSAES)
or other techniques.
The point of this is that alloy manufacturers know how to test their
products for the specification elements. Every batch of alloy
produced at a steel mill or foundry will be analyzed. Therefore,
there should be an analysis report somewhere in the supply chain. If
the parts supplier doesn't care enough to keep a copy of the analyses
for the alloy they buy, they should at least be able to get a copy
from their supplier.
Be aware that not all of the restricted substances are analyzed in
alloys. You are quite likely to be told that it makes no sense to
test for Br in steel or aluminum. Even if a flame retardant compound
were dumped into the molten metal, it would vaporize and be gone
(quantitatively) almost immediately. You are also likely to be told
that testing for Hg is not done for many alloys or metals for the
same reason. There are some folks looking into the possibilities of
having Hg show up in aluminum, but to my knowledge, it is highly
unlikely to find any. For Cr, the hexavalent form will not be found
in alloys. Therefore, if the supplier is willing to swear that no
hexchrome coating was applied, you are safe regardless of how high
the Cr content is.
The preceding diatribe is not comprehensive and I am not a
metallurgist. I advise some common sense and perhaps some dialogue
with the ASTM E01 or ASTM F40 folks about these issues.
sincerely,
John Sieber
At 05:07 PM 8/10/2006, you wrote:
>Genny,
>
>Things like 6061 aluminum are standard alloys of known
>composition. For example, 6061 is:
>
>Component Wt. %
>Al 98
>Cr 0.04 - 0.35
>Cu 0.15 - 0.4
>Fe Max 0.7
>Mg 0.8 - 1.2
>Mn Max 0.15
>Si 0.4 - 0.8
>Ti Max 0.15
>Zn Max 0.25
>
>Regards,
>Brian Epstein
>Sr Regulatory Compliance Engineer
>Veeco Instruments
>[log in to unmask]
>ph 805-967-2700 ext 2315
>fx 805-967-7717
>ce 805-591-9587
>
>
>
>-----Original Message-----
>From: Leadfree [mailto:[log in to unmask]]On Behalf Of Genny Gibbard
>Sent: Thursday, August 10, 2006 10:32 AM
>To: [log in to unmask]
>Subject: [LF] Metal compliance
>
>
>Anyone else having major difficulties getting RoHS compliance statements
>out of your metalwork suppliers?
>We have companies that provide things like chassis parts, custom
>standoffs, etc. They are made of things like 6061 Aluminum, stainless
>steel, etc. These are things that can use the exemption:
>
>6. Lead as an alloying element in steel containing up to 0.35 % lead by
>weight, aluminium containing up to 0.4 % lead by weight and as a copper
>alloy containing up to 4 % lead by weight.
>
>However, our metalwork vendors are having trouble getting any sort of
>statement out of their raw materials suppliers, so they are reluctant to
>issue statements to us.
>
>I don't know if it would be an unlikely thing to have higher than the
>0.4% Pb in aluminum, or if you need to have some carefully controlled
>source of aluminum in order to achieve that.
>
>Any thoughts?
>As always, your help is much valued and appreciated.
>
>
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John R. Sieber, PhD
Research Chemist
National Institute of Standards and Technology
Chemical Science and Technology Laboratory
Analytical Chemistry Division
100 Bureau Drive, Stop 8391
Gaithersburg, MD 20899-8391 USA
[log in to unmask]
Tel: 1.301.975.3920
Fax: 1.301.869.0413
www.cstl.nist.gov/
Identification of commercial items in this document does
not imply endorsement by NIST or that items are
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