replying to John B. , Bob Lowe wrote:
slocombjb wrote:
A substantial amount of the high performance sailboat masts and spars
are 6061, usually marked "T6" :-) I've no idea why as 5052 and 6061
are roughly the same strength so I assume it has something to do with
availability or cost.
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Cheers,
John B.
Again, just my opinion. When I first read that some one said that T6 was
not a proper 'grade' for aluminum, I thought,wait a minute...I have heard
many times things like, "Use T6" or "Get me some T6" or "T6 will do just
fine." We know that that the full Identification number of a metal alloy
is the chemical make-up of the alloy and of course 6061 is a common one.
If someone says 'use T6', and knows what he is talking about, he is saying
that I don't really care just what the alloy type or alloy number it is,
just that the 'T6' is tough enough and suitable for the job and some types
are not adaptable for T6 hardening so he is covered. If 6061-T6 is
specified, they are just being more specific, which in my opinion is okay,
but not required in some circumstances. As for the 5052 and 6061 alloys
having about the same strengths, I would think that there are many
aluminum alloys that have similar strengths but have other different
properties, such as corrosive resistance, and as you say, cost and
availability could be major factors. One time in LA I bought a boat and
after a year or so I noticed that some of the aluminum hardware had turned
to a white dust and I bought some 'boat' grade stainless as replacements.
Maybe the 'boat grade' could have been more specific of course.
And as for the Aluminum Billets can not be of cast as someone said...I
don't believe this....As far as I am concerned, Cast Aluminum Billets have
been made since Aluminum has been used - All billets are not created
equal. A lot of people get too hung-up on semantics and specifics....That
may or 'may not' be correct. Again, just the way I see things. After a
little crash-course on 'Aircraft Quality', I am okay, not great, but okay.
Thanks.
Bob Lowe
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