On Sat, 13 Mar 2010 12:58:27 -0600, Louis Ohland
wrote:

On 3/13/2010 12:52, Ned Simmons wrote:
On Sat, 13 Mar 2010 12:05:24 -0600, Louis
wrote:

Looking for 4340, annealed, in 1" x 2" size. Length is 4" minimum.

Speedy, Metal Express, and others do rounds, and I'm not ready to carve
a rectangle from a round.

Do you really need 4340? I think the major difference between 4340 and
4140 is hardenability. If you need maximum strength all the way thru a
large section 4340 is indicated, if not, short pieces of 4140 flat
will be easier find.


Looking to heat treat to Rockwell C 35, Tensile strength 160,000psi,
yield 138,000psi, or there abouts.

You are exactly right on 4140 being easier to find...

It looks to me as though you might be able to get Rc35 all the way
thru a 1" thick 4140 piece, but 4340 would certainly be more reliable.

BTW, I'm looking in "Modern steels and their properties," the best
reference I've seen for this sort of data on alloy steels.
Unfortunately I can't find an online copy.
http://openlibrary.org/b/OL5528277M/...eir_properties

--
Ned Simmons