How bad is it? or Stainless steel not so stainless afer all

Hey guys,

I've recently bought an all stainless steel razor that seems to stem from some old military stockpile. When I got it, it was completely new, sealed in a plastic sleeve.

After taking a closer look, I found some very small black spots, very close to the edge. I took some pictures with the microscope.

My question is, how do I stop it, how bad is it and if it's bad, how can I remove it?

Thank you very much in advance.

Overview:



Three spots from a closer view:

That's not bad just some white diamond polish or some mothers aluminum polish on a rag should get it or try some toothpaste on your finger tip

Stainless should be written stain less -- it's not totally corrosion proof, just much less prone to corrosion than carbon steels.

Some of those spots look more like voids to me than corrosion, but it's hard to tell from a photograph. At any rate, any spots should polish off.

Peter

I think if you looked at any stainless steel item under similar magnification, you would see similar results. Stainless steel is not magic, just steel with a high nickel content. Anything made of steel will rust, or oxidize, if that term is more pleasing.

So you guys think it's just some spots and not pitting/rust?

For now I just put some vaseline on and put it back in the drawer.

I'm sorry for the bad picture quality, but I was in a rush to catch the train and won't be back home for a week, so I can't even take new ones.

It should clean up quite nice. I have gotten good results from blades in worse condition than this. A good hand polishing and stropping should fix it right up.

LookingAtPictures said:

For now I just put some vaseline on and put it back in the drawer.

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If you want to protect the blade, there are better solutions than vaseline.
Ballistol springs to mind, but there are other compounds that work equally well.

To my way of thinking; if you have enough razors that you can think about putting razors in the drawer then you need something better than vaseline.


B.

The problem with traditional stainless steels is that for an application such as making a razor there are confilicting requirements. Proper stainless tradiitonally has 18% chromium and 8% nickel. It is the formation of chromium oxide on the surface that prevents corrosion.

Surgical steels have less chromium and are therefore not as resistant to corrosion as 18/8 is but their carbon content means that they can be hardened sufficiently to make razors and scalpels &c.

No doubt there are modern alloys which may well do the job. However I have here at home a fairly expensive kitchen knife. The blade reads X50CrMoV15. This might mean something to some of you - I prefer to think of Kayser Ellison and EN numbers, but then I'm an old fart!

The point is that this quite costly knife does not keep its edge very well; it is nowhere near as good as the very old and rather lovely Spanish carbon steel table knives I have. They are seriously sharp and tend to stay that way!

C.

Lol, no one is ever going to try to make a razor out of CROMOVA steel! That "German" knife is designed to be totally bash proof, not actually sharp -- normal edge is 20 degrees per side. The edge bends over instead of chipping, and needs to be "wiped back up" constantly with a smooth steel. The steel itself has very large chromium and vanadium carbides in a fairly soft steel matrix (RC56 typically, much much softer than the normal RC 62-64 for razor steels). Those big carbides on a fairly obtuse edge provide great wear resistance, but it's impossible to form a fine edge. The big carbides rip out of the steel, leaving a soft swiss cheese like steel behind that fails on the first contact with anything hard (like a cutting board). Carbon steel of the same Rockwell C hardness with take a much better, sharper edge and hold it longer.

There are better steels for knives -- "swiss razor steel" (27C19 or 19C27, I can never remember which) is common in Japanese stainless knives, so is VG-1 and VG-10, typically sandwiched between softer stainless to reduce breakage, they are fairly brittle.

440C stainless appears once in a while in razors, it's OK but unless handled very well tends to have very large cabides, similar to ChroMoVa steels.

Stainless steels with high carbon so they can be hardened are significantly less "stain less" than 18/8.

Use Camelia oil or something similar to protect steel from rusting. Vaseline would be OK, but only if it's pure hydrocarbon and not scented, etc. Oils are much easier to remove.

Peter

Indeed my point exactly - so this stuff is "Cromova" is it? Well in the event I buy more knives I shall avoid this one.

I see that 440C comes into the category popularly known as "surgical steels"; it has no nickel content with 16 - 18% chromium and around 1% carbon. I have here a German razor stamped "surgical steel" (and "Thursday"!) it shows no marks except on the tail. I have bought two of its brothers (Saturday and Sunday) to keep it company!

C.

if they are truly black its possible its magnetite. which is a chemical conversion of iron oxide. but since you need a scope to look at it, polishing would be fine. but like everyone has said stain-less steel is not corrosion proof. it takes more than carbon steel. just use the magnet test to see if its really stain-less or plain carbon steel

High carbon stainless steels that can be hardened are normally "magnetic" -- the magnet trick can be misleading. No or very little nickel, and moderate to stainless levels of chromium.

For kitchen knives, look for Japanese steels -- Hitachi blue or white for carbon steel, things like AEBL, VG-10, "razor steel", etc. All are harder and take a finer and longer lasting edge than CroMoVa steels. More brittle, so no prying caps off or opening cans with them, though, and a smooth steel will NOT do much for maintaining an edge (it's softer than the knife).

Peter

psfred said:

High carbon stainless steels that can be hardened are normally "magnetic" -- the magnet trick can be misleading. No or very little nickel, and moderate to stainless levels of chromium.

For kitchen knives, look for Japanese steels -- Hitachi blue or white for carbon steel, things like AEBL, VG-10, "razor steel", etc. All are harder and take a finer and longer lasting edge than CroMoVa steels. More brittle,

so no prying caps off or opening cans with them

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, though, and a smooth steel will NOT do much for maintaining an edge (it's softer than the knife).

Peter

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Good heavens! Do people do this!!?

C.

Friodurs are made of 440C.

They aint too shabby.

440C used to be the "wonder steel" of stainless knives. There are better alloys these days, but I don't think a 440C razor would be something to sneer at. After all, my 440C Chicago Cutlery knives work pretty well. My Tojiro in VG-10 is better, but not by all that much.

A razor in AEB-L would be fun to have, but probably a real bear to hone.

And yes, people do open cans and pry bottle caps off with kitchen knives, I suspect mainly because you can with a soft CroMoVa knife and just bend the (blunt) tip a little. It's possible to cut paper with a razor too, but you may not like the condition of your face if you then try to shave with it....

Peter

this makes me wonder what some of the best steels are, i see a lot of O1 tool steel, the more edge retention any edged implement has the harder sharpening and honing is.

psfred said:

Stainless should be written stain less -- it's not totally corrosion proof, just much less prone to corrosion than carbon steels.

Some of those spots look more like voids to me than corrosion, but it's hard to tell from a photograph. At any rate, any spots should polish off.

Peter

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Indeed, and I have a stained Titan to prove it.