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Thread: CRS Cracks?

  1. #1
    Join Date
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    Default CRS Cracks?

    Yesterday I chucked up a piece of 2-1/2" diameter steel I presumed was cold rolled rod. I'd gotten it in a gift box of short pieces from a friend who got a bigger box of unknown steel from a salvage yard.

    As I turned it down to around 2" diameter, I got a reasonable finish, but the entire thing is peppered with these tiny cracks. Is this "normal" for cold rolled, an artifact of poor processing, or . . .?




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  2. #2
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    Default

    Sometimes in the rolling process the steel gets 'laminated'. I've run into this before and the cure is to just chuck it and start over. Just as an aside; We would 'ring' our cam blanks before we cut them. Any one that went 'thunk', when struck would be tossed. From my experience it happens a lot more in HR plate.

  3. #3
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    At the last place I worked we magnufluxed our stock before we made critical parts out of it, looking for exactly the flaws your photo shows. Unless you're making something critical, like a revolver cylinder, cannon tube or other high stess part, it will most likely be fine.
    Ignorance is curable through education.

  4. #4
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    We used to call pieces of steel in this condition "Rerolled Railroad Track". I have seen parts weep rust out of these cracks when flood coolant was used. A friend of mine sent a few ton of this type of back to the supplier when he found it had had voids in it. Poor processing, and probably the percentage and quality of the scrap put into the mix.

    Frank

  5. #5
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    I don't know where/who the CRS is coming from but the HRS and structural stock down here is being suplied out of Mexico, India and Bangladesh. It bites my arsh that prices are edging up again and the quality is going down.

  6. #6
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    Cold rolled isn't really rolled, it's drawn. What you have there is little bubbles elongated in the drawing process. Something caused excess dissolved gases in the melt when it was poured. And, no, they aren't "normal" for cold drawn steel.
    Free software for calculating bolt circles and similar: Origin now settable to bottom left! All values positive. Click Here

  7. #7
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    Have had similar experience with off cuts from a scrap yard,(probable the reason they were there).

  8. #8
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    Never look a gift billet in the cracks...

    BW

  9. #9
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    Default

    Quote Originally Posted by Evan
    Cold rolled isn't really rolled, it's drawn. What you have there is little bubbles elongated in the drawing process. Something caused excess dissolved gases in the melt when it was poured. And, no, they aren't "normal" for cold drawn steel.
    Isn't it more correct to say that round stuff is drawn, and flat stuff is rolled?

  10. #10
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    " Isn't it more correct to say that round stuff is drawn, and flat stuff is rolled?"

    Nope, flat bar is drawn.
    Free software for calculating bolt circles and similar: Origin now settable to bottom left! All values positive. Click Here

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