Don Foreman wrote:

On Mon, 02 Jan 2006 14:43:03 -0500, Leon Fisk
wrote:


On Sun, 01 Jan 2006 09:47:16 -0600, Wayne Cook
wrote:


On Sat, 31 Dec 2005 21:38:27 -0800, "Harold and Susan Vordos"
wrote:


"Wayne Cook" wrote in message
m...

On Sat, 31 Dec 2005 17:22:35 -0800, "Harold and Susan Vordos"
wrote:


Don't get the wrong impression, Wayne. I'm not hot, nor was I upset by your
response. Just adding more comments to what is a good conversation and a
learning experience for everyone that isn't familiar. I figure you and I
have exchanged views long enough that we understand one another.


Agreed.


To quote what you said earlier:


I'm afraid I'll have to disagree at least a little in this
statement. I actually believe that 4140 was developed to be a high
strength material that could be welded reliably.

The material in question here is actually 4130, not 4140 or the others
(4340 is chrome nickel moly). 4130 is low enough in carbon that it won't
heat treat hard enough to create the problems the others do, and *can* be
welded reliably.

Ok. I'll buy that. All of my higher alloy stock like that is unknown
so I can't pin down the exact alloy. Experience has taught me how to
recognize that it's one of the chrome molly alloys when I do run
across it though.

Just to add to this discussion...

I walked out to the garage and took a look. My old Schwinn
Probe mountain bike frame claims to be True Temper Chrome
Molly 4130. As you can imagine, it has quite a few welds on
it. This was only a low end bike a good many years ago now
when Chrome Molly frames were quite popular. The frame has
held up well (~40,000 miles) and is quite stiff. For the
price I paid for it (~$350), it can't be too difficult to
weld.


Airframe builders weld 4130 routinely, usually with O/A.
Bikebuilders do too, usually with TIG.




The problem with welding 4140 is that the surrounding cold metal
quenches the weld too fast and you get stresses and hard spots in the
wekd because of the higher carbon content. A simple solution for
welding 4140 is to preheat the metal to about 400 degrees F. so that it
will not quunch the weld and make it brittle.

John

Gunner Asch wrote:
Whats the best way to make a square hole in a round piece of material,
without a broach? The round rod needs to be split, (snip)

Gunner

There's a nice article in one of the 80's Projects in Metal issues that
covers just this procedure. I believe another poster here has already
described something similar, but if you want the article, let me know,
I'll email it to you.

--
Gary Brady
Austin, TX
www.powdercoatoven.4t.com