4140 is also known as chrome-moly. It is a non hardening high strength
steel used for things like air frames, bike and race car frames. Lots
of other applications too. Very useable in rod, sheet and tube shapes.
It's a bitch to forge and machine. It's tougher than the hubs of Hell
and welds very well. It is also very pricey. If it's at scrap price
I'd get me some pardner.
P.S. sorry about the "off topic rebuff" dude. Can we still be friends?
I will have to go back and double check it. This number was on a lable
but it was unclear if this was the material type or just some other
number that happens to mean something to us but some paper pusher is
using it as a invoice or po number.
If I remember right the stuff had a dark almost a smooth rusty layer on
it but it might have been dust. I think it was about 1" solid rod about
10ft long. I'm use to thinking of chrome-molly as a tube used in bike etc.
I'll look tomorrow and report back. I most likily will just have a few
more questions:-( I'm still learning what is important to look for.
Thanks for all your help.
Well, if it's SAE 4140, then it's a molybdenum alloy with one percent
'moly' and .4 of one percent carbon. It's commonly used for structural
apps and fasteners such as bolts. It is a deep-hardening oil quench
steel. In the past in aviation it was used for tubular airframe
structures, but there were cautions on it concerning hydrogen
embrittlement after welding. I have also encountered problems in hammer
welding as the alloy tends to form an oxide skin with a very high fusion
temperature. I use it normalized for pressed-in pin stock for its wear
characterists against hardened 5160 blades.
Hope this helps...
Lots of power hammer dies are made from it.
I think you'll find that 4130 is more often used in tubular form for
frames. It would be a little LESS hardenable and that would be
desirable for welded structures.
4140 is a high hardenability chrome/moly alloy steel. Its as quenched
(oil) hardness is 601 Brinell. Compare that with 1095 which is
601Brinell water quenched and 4130 which is 495 Brinell oil quenched.
601Brinell is about 58 Rockwell C and 495 Brinell is about 51 Rockwell
My guess would be that 4140 hardens deeper than 4130 in larger
sections, maybe above 1" diameter. 4340 is through hardening in pretty
large sections, so it's reasonable that 4140 is something between 4130
4140 is a good tough steel, not as tough as 4340 and not as weldable
4130. I think it would be great hammer material.
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