cast iron or cast steel-how do i tell??

I have a project Ive been aproached with and would like to know how i can tell the difference between cast iron and cast steel. The part is a front axel housing from a four wheel drive John Deere tractor, from the early 80s Id guess. I need to machine a disc (will look like a washer) and weld it to the housing to repair a worn area. Im just curious how do i tell if its cast steel or cast iron. It looks like cast iron, I have not hit it yet with the grinder to look at the sparks. Does cast steel look like cast iron when ground? I remember seeing a chart that showed "spark testing" colors and appearence but cant remember where. Thank you for any help you can provide,

Craig

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If you can turn a bit of it in a lathe, curlies indicate steel. Crumblies indicate cast iron. ;)

Wes -- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller

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I cant put it in the lathe, its a front end housing from a tractor, i dont remember where the spark testing pictures were, but they showed you what different materials looked like when you hit them with the 4" grinder, but im having trouble finding the pics (had them in an old machine shop textbook but cant find it) thank you for your response.

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When you are machining the stuff, it is easy to tell the difference but since you can't.

Well, then, try this.

http://shopswarf.orconhosting.net.nz/spark.html

Suggest you get some steel and cast iron to try against the wheel to calibrate yourself before making a determination.

HTH

Wes

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Thanks guys for all the help!!

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There is a great deal of carbon in cast iron and when cut, you get the carbon smell in the air. Steel melts at such heat the carbon would be burned off and absorbed.

Iron also flakes and is slick due to the carbon.

Martin

Wes wrote:

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I came in late, and didn't see the other posts, so I may be repeating.

Get a book on metalworking. The "spark test" will tell you about as clearly and simply as any way. Grinding a piece of metal (in informed hands) will pretty easily tell you the character of the piece.

Lloyd

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Early 80's Deer axle will be cast iron. Late 80's - current and the later Yanmar chore tractors will have cast steel front axles.

If this is one of the early small JDs it will be cast iron as well.

--
Steve W.

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Thank you all again for the responses, the machine is a John Deere 2240, 1982 four wheel drive (mechanical) the owner says. He tried to locate another housing and had little luck, the one dealer told him this particular axle was used from 1979 to 1982, his opinion is that its junk now the way it is so I may as well give it a try anyway. I also have to cut a sleeve and thread it internally for a trunion to thread into, but its metric threads and my machine doesnt have that ability. So, gonna have to figure out something there also. He is gonna let me know after the weekend if he wants me to give it a shot, he has a couple more places to look, but the one he did find was very expensive and didnt look much better in the picture. Thanks again for your help and advice, Craig

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monkers wrote:

I'm going to make two _guesses_, and you can take them for what they're worth:

I _guess_ that a spark test will tell, just as if it were a cast iron rod and a steel rod. Cast steel is steel, it's just cast.

I _guess_ that you can weld your disk on with nickel, or braze it on, and it'll be just as strong either way. Unless you want to duplicate the material with the disk, this may be the most expedient way to go.

--
Tim Wescott
Control system and signal processing consulting
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"monkers" <> wrote in message

It sounds like you are concerned with weldability so why not just do the old fillet break test. Take a chunk of scrap metal and try to weld it to the housing. Warm up the housing a bit first to dry it out and to slow down the cooling rate then run a fillet weld(7018)on one side only and let it cool. Then break it off with a hammer and you can tell if it'll work or not. If it's cast iron it'll break easy, if it's cast steel it'll be much stronger to break and it should break down the center of the weld, if it does Bob's your uncle... If it's cast iron weld it with nickel rod 55. phil

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monkers wrote:

Hi Caig, The simplest test is the chisel test. Sharpen a cold chisel well, then chisel into the housing away from where you want to weld it. Steel will come out in ductile shavings just like drill shavings, cast iron is much greyer and comes out in chunks. Because its not ductile.

Hope this helps. On to repairing it . need to see a picture before making any suggestions. Being a farmer as wekll as a metal craftsman I knownly too weell how old tractors need mending.

Ted in Dorset UK

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