In a message dated 97-04-16 03:33:00 EDT, N6TT@worldnet.att.net (Steve)
writes:
> After calling a dozen tubing companies in LA, I found a place that has 500
> foot of
> chromoly 2" O.D. .250 wall, ranging from 17-24 foot. My question is they
all
> said there
> material is 4130 grade, is this standard? Cant seem to find any other
grade..
While there are many carbon steel mast types, most steel suppliers only
seem to stock 1026 or 1027 and 4130. Special ordering other varieties may
not be cost effective.
Chunks of steel tubing come in "20 foot randoms"; that is they can be any
length from 17 to 24 feet as you've mentioned. The trick is to order a
minimum length, say 20 feet. I just ordered three 2 inch OD 4130 masts and
they came in 24 foot lengths. Also ordered a 3 inch OD 4130 and it was 24
feet 6 inches - a big hunka steel to say the least.
You can also check the pedigree from your supplier. The masts I
ordered were classified as MIL-T-6736 - A/B Cond. N. and it has a yield
strength of 70,000 psi. I don't have all the specs on the MIL designation
but will report back when I get some additional info. Can any TowerTalkians
elaborate on this?
73, Steve K7LXC
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