The Armour Archive

I worked with some steel recently... supposed to be 16 ga. mild... but there's just no way.

The stuff was cut resistant (I use a jigsaw) and a bit hard on the blade... but not near as tough as stainless... which tends to burn out blades fairly quickly... but much tougher to cut than mild.

The stuff was darn near as hard to shape as stainless... but not quite, I think... though world more difficult than normal mild of the same guage.

Finally, when sanded to a shine, I'd almost swear it looked more like a stainless shine than a mild shine.

Any notion what I was working with?

A soft stainless that isn't absolutely rust resistant, perhaps, but harder to rust than a mild formulation would be.

Or a nickel steel alloy, though these are uncommon. It workhardens a lot; there's a clue.

Other then Steel", no. I can give you 9 pieces of steel from 0.1% to 0.9% carbon anf they will have a spectrum of performance. Then I can take those same steels and work-harden them and their performance will change again and then I can heat-treat them and change it again. and THEN I can alloy it with chromium and nickel to make stainless. Even then I can give you annealed 410 and work-hardened 304 and convince you that the spring-steel is the softer.

Step 1: check it with a magnet. If it doesn't stick then it's a type of stainless. If it does stick it still might be stainless but work hardened. Heat up some scrap and slow cool it. If it looses it's magnetivity or just drops then it's probably stainless. If it doesn't it still might be stainless. You can spark-test it which might help or you can take a piece of known stainless, known mild and this then spray with vinegar or muriatic acid or whatever and allow it to weather... and even if it rusts it might still be a type of stainless. There is no really way to know without a metallurgical test.

Sorry.
Sean

Sean Powell wrote:There is no really way to know without a metallurgical test.

Sorry.
Sean

Pretty much. There are some extremely tough alloys that are high nickle content that will look a bit like SS.

Where did you find it, were there any markings?

first thing that came to my mind was cold rolled.

The large metal recycler near me has some sort of laser gun that does metal analysis.

How is it with a magnet?

Those xrf are fairly cool, the newer models will tell you a lot more about what's going on at the molecular level.

You may have a piece of alloy steel like 1050 or something.
Without a metalurgy test its hard to tell what you have.
I think Someone on the archive was running tests at cost but I'm not sure who.

losthelm wrote:Those xrf are fairly cool, the newer models will tell you a lot more about what's going on at the molecular level.

You may have a piece of alloy steel like 1050 or something.
Without a metalurgy test its hard to tell what you have.
I think Someone on the archive was running tests at cost but I'm not sure who.

If I hadn't quit my old job I had access to one. Didn't use it much but it was useful at times. It would be better if the one we had could measure carbon but that was too light of an element. Didn't matter much for the stainless we worked in.

Sean

Sean Powell wrote:If it doesn't stick then it's a type of stainless. If it does stick it still might be stainless but work hardened.

Dead soft 410 is magnetic.
Last year I made my dad a spring clip for his truck's sunshade that he can stick magnets to, and it's not going to leave rust stains on the fabric.

But as to the OT, I would have guessed 4130 or 4140. They're "almost stainless" and would be a lot harder to form than mild.
Take some and play with heat-treating it, in addition to the spark test.

schreiber wrote:

Sean Powell wrote:If it doesn't stick then it's a type of stainless. If it does stick it still might be stainless but work hardened.

Dead soft 410 is magnetic.
Last year I made my dad a spring clip for his truck's sunshade that he can stick magnets to, and it's not going to leave rust stains on the fabric.

Good point. I also recall that 420B & C and 440 C are magnetic without work hardening. (not sure about the other letter designation) They all get more magnetic with work hardening though.

Net result is the same. If a magnet doesn't stick then it is stainless but if it doesn't it might still be a magnetic stainless.

Sean