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Posted to rec.crafts.metalworking
Don Foreman
 
Posts: n/a
Default Group question on machining something

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
...
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.