I bought a 1.75x20'x.120 stick of what I thought was HREW (that's the inexpensive common stuff right?). But this stuff is really silvery shiny and dosen't have a weld seem on the inside (its welded it just dosen't have the bump on the inside or outside). I wonder if they loaded me up with DOM by mistake? Does HREW have a bump on the inside where the weld is?

Not always, and sometimes DOM does ;)


okay, seriously. I've seen HREW with barely any raised seam inside and I've seen DOM with a visable seam inside.

All the DOM that I have work with is typically dark brown is color, almost black. The HREW that we see daily for the most part is shinny in color and has a some color on the outside from heat, the Inside looks to be pretty smooth.:)

Ohhh good point about the color

does it have any stampings on it saying what alloy it is or anything? Those will usually tell you if you know how to decode it.

Also, HREW usually comes in looking "cleaner" than DOM, with a fairly lustrous surface, and a dark line where its welded.

DOM is generally still pretty oily from the plant processing.

Originally posted by foley

Also, HREW usually comes in looking "cleaner" than DOM, with a fairly lustrous surface, and a dark line where its welded.




Yea, this stuff was really clean with a blueish line where it was welded. It's just the lack of any sort of seam on the inside that threw me off. Thanks for the responces guys.


:cool:

Originally posted by fatkid
All the DOM that I have work with is typically dark brown is color, almost black. The HREW that we see daily for the most part is shinny in color and has a some color on the outside from heat, the Inside looks to be pretty smooth.:)

Isn't DOM just "Drawn Over Mandral". A process that can be done to HREW. Are you talking about chromoly? It is generaly darker.

Originally posted by KYODER


Isn't DOM just "Drawn Over Mandral". A process that can be done to HREW. Are you talking about chromoly? It is generaly darker.

It can be done to anything, but it involves oiled dies and a LOT of force, which pushes oil into the pores on the surface of the metal, and leaves it kinda brown colored. Hence the fact that you need to clean it up before you weld on it.

Thanks, that is what I thought. The DOM I have worked with has always been cleaned prior to me getting to tweak it.

ya but like some of the other guys said. There is a big color difference. Just spray some carb cleaner on it and you will know right away if it is DOM or HREW

While we are on the subject what is a good way to clean the oil off of DOM in preperation to weld?

JYS

Originally posted by Junkyard Slug
While we are on the subject what is a good way to clean the oil off of DOM in preperation to weld?

JYS

good call, I was gonna bring that up as well

I typically wipe it down with acetone, then sand it with 100-120 grit sandpaper, and then wipe it down with the acetone again before welding.

My buddy (IHRA chassis builder) taught me to weld, and he recommended acetone because it leaves practically no residue on the material after it evaporates.

What cleaners have others of you had success with, and what welding process followed it?

Mine is all heliarced after cleaning.

At work, we used acetone, or non-chlorinated brake-kleen. Works good. Same thing for some of the CRS plate stock that we got that was oily. Make sure it all evaporates, that shit burns FAST!.:eek: All prep grinding was done with 80grit roto-locs on the 2". not sure whey you'd need any better surface finish.:confused:

Originally posted by FCwheeler
At work, we used acetone, or non-chlorinated brake-kleen. Works good. Same thing for some of the CRS plate stock that we got that was oily. Make sure it all evaporates, that shit burns FAST!.:eek: All prep grinding was done with 80grit roto-locs on the 2". not sure whey you'd need any better surface finish.:confused:

it's not a matter of needing better, just that the 120 grit takes enough material to get it clea, so why go heavier?

I've used brake cleaner with good results, but my shit ain't as bitchin as my "mentor's" so I go with his advice on stuff that matters.

it's HREW and I use to ue actone but now brake cleen in the can...what ever was handy

All that cleaner evaporates fast enough to not cause a fire? I cleaned with brake kleener once and waited about 5 min. it still flamed on me, but maybe I still had some residue. I've always stuck with acetone.

Originally posted by foley
does it have any stampings on it saying what alloy it is or anything? Those will usually tell you if you know how to decode it.

Also, HREW usually comes in looking "cleaner" than DOM, with a fairly lustrous surface, and a dark line where its welded.

DOM is generally still pretty oily from the plant processing.


ahhhhh good, I just thought my supplier was a fawking pig stye !!:D

It is possible to get HREW tubing with the seam ground inside and out. It all depends on if you want to pay for it. .....what application you are buying it for.

I was under the impression that DOM was srawn from a solid rod (not HREW that was drawn through a finishing die). Any comments from someone in the tubing industry?

Originally posted by Flipper
It is possible to get HREW tubing with the seam ground inside and out. It all depends on if you want to pay for it. .....what application you are buying it for.

I was under the impression that DOM was srawn from a solid rod (not HREW that was drawn through a finishing die). Any comments from someone in the tubing industry?

look closer at your DOM tube, if you know what to look for you can see the seam and where i t was pressed smooth.