OK, here's what I need to say first, "I'm actually not an idiot. And, if necessary, I can prove it." But, here's a funny story and maybe you can confirm what my funny story's mystery metal is from the photos I'll attach here later on. However, here's the story.
Today I needed some solid steel rod to turn in my little lathe for a part I need to make for my Panhard rod mount. It needed to be at least 1-1/4" in diameter, but slightly larger would be OK as I would just turn it down a little more. I called around to all the steel suppliers in my area of North San Diego County, but none of them stock anything in that large a diameter. So, I also called the local metal salvage yards too as I didn't want to drive to San Diego where I knew for sure they had it in stock, but would charge me an arm and a leg for a small quantity. One of the local yards said, "Yeah, we have a whole bunch of salvage stuff and we're marking all remnants down to 25 cents a pound for a sale today." He was sure that had a bunch of stuff in the range of 1-2 inches. So, off I went to a town about 12 miles away.
He was right. I found a piece about 4 feet long (most of them were 5-10 feet and too big for me) that looked promising. It had been cut with a torch at one end, but the other had nice, coarse threads machined into it. "Oh good, I thought, it machines up just fine." It was heavily oxidized, but also over 1-1/2" in diameter and I thought I'd just take 1/8" off and find nice metal underneath, no problem. Here's what it looked like:
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Mystery-Metal-B.JPG
Attachment:
Mystery-Metal-A.JPG
I got it home and decided I'd clean off all the oxidation and the cut it in half for storage. There's no way I'll ever machine a 4' long part. Once the oxidation started to come off, I could see it had an unusual texture on the metal. It almost looked like a textured paint, but it cleaned up pretty quickly, but never got shiny like a true metal and the texture stayed put. A wire wheel on a drill couldn't get it off. OK, I said, let's cut off the threads as they're not useful and would be very annoying to deal with on the lathe and I'll just machine the texture off on the lathe.
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Mystery-Metal-2S.jpg
After about 20-30 strokes, I noticed the blade was no longer taking a bite, but just slipping through the metal and not doing much. I looked at the blade and saw the teeth were just about gone completely. "Wow, I said to myself, this stuff is super hard. What in the heck is this stuff?" I had an old bi-metal blade around that I had purchased to saw stainless steel with and decided to go find it and try that blade instead.
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Mystery-Metal-3.JPG
That worked much better, and it took some effort, but I got through the metal, but knew it was too hard to be useful in my Panhard rod application. Still, I wanted to figure out what kind of metal it was. So, here it is after I sawed through.
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Mystery-Metal-5S.jpg
I said, "Shoot, that sure looks like stainless steel to me, but how did it get so oxidized and what in the heck is the coating on it?" I polished it up and here's what it looks like.
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Mystery-Metal-6S.jpg
I think it's stainless steel with some kind of weird coating that oxidizes like mild steel. Lest you think I'm goofing on you, here's the piece going from a raw, oxidized state to revealing the textured coating after I wire brushed it with a wheel.
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Mystery-Metal-CS.jpg
I think just about anyone would be fooled by this one, don't you? Does anyone have any idea of what kind of situation would use this kind of stainless steel? It seems to contradict the purpose of stainless. Do you think it's coated with some kind of mill scale and that's what is high in iron content?
All is not lost. I paid 25 cents a pound and I think I can sell to another salvage yard as stainless for much more, maybe a couple of bucks a pound? But, now I have to go to San Diego anyway. Arghhhh!
Cheers,