chro mo vs. dom/hrew

DOM and HREW are both mild steel (usually 1020) and can easily be welded with MIG (or stick). The chromoly (4130) tubing is an alloy of steel, chromium and molybdenum and is quite a bit stronger and more expensive than mild steel. Most mild steel yiled strength is in the 60,000 psi range where as chromoly is in the 95,000 psi range.

Although chromoly can be welded with MIG, TIG is prefered and the welds must be heat treated after welding to relieve stress.

There is a good article on the FEB 06 4wheel and off road mag

flame heat treated??

we flame harden rolling mandrels and pilots for some stuff, is this similar? Guessing all for some added toughness/hardness?

On 2005-12-13 19:18, mejonesrebel wrote:
flame heat treated??

we flame harden rolling mandrels and pilots for some stuff, is this similar? Guessing all for some added toughness/hardness?

Click to expand...

I'm no TIG expert but I'm pretty sure it's the opposite. With Chromo, when you weld it it gets brittle if not pre/post heated. If you cool it down too fast the weld area is actually weaker since the area surrounding the weld is brittle and can snap. What the post heat is doing is stress relieving actually softening the area, I believe.... Or making it more uniform... :

Don

actually 4130 is weldable by mig and tig. in order to get the benefits of the metal though you have to heat treat it after welding. otherwise its just about the same as mild steel.

4140 is only by tig and needs special care or its very brittle.

According to Lincoln, you only have to stress relieve (heat treat) 4130 if it's thicker than .120" wall.

http://www.lincolnelectric.com/knowledge/articles/content/chrome-moly.asp

in my opinion, HREW is fine for an off-road rig cage.... DOM is race car {expletive}

In my opinion, HREW is ******* {expletive}. Lol haha come on mods have SOME sense of humor!

when I redo my cage I am going to use DOM as well as my sliders and exo. My current cage is HREW and it has held up fine so far but with one good roll on it and how easy it bent and dented I am considering DOM now. I will probably use .120" wall for almost everything and then .188 for the sliders.

cromo is in my opinion is then best but not as easy to work with like DOM or HREW and most of us don't need a cage that can handle a 120 mph roll when I flipped my junk it was backwards and the windshield frame and cage too the most of it but the cage got it worse it was wierd