Sanrenmu 710 full of stains

[jalbam]

Hi,

I have had a SanRenMu 710 folding knife for just a few days, five or so. I have only carried it with me in my pocket a couple of times and most of the times it has been lying on my bedside table. It has never been under any abnormal humidity condition and I don't have sweaty hands but it shows several spots (freckles, stains) in all its parts: handles, blade and even clip.

Did anyone experience the same with this knife? Is that normal with all or almost all stainless steel or just with cheap ones? Can this affect blade sharpness? What can I do to clean it? Is there any method to avoid it?

Here you have some pictures:







Thank you very much in advance!

[enki_ck]

Clean it with some window cleaner (not a joke). All steel rust, some faster than others, Sanrenmu uses the same steel as Spyderco in their  Ambitious/Persistence/Tenacious/Resilience line and all Byrd knives so I wouldn't call it a cheap steel. And even a small amount of sweat can cause rust, high salt content.

[jekostas]

That's pretty normal with brushed-finish stainless steels.

[jalbam]

Thank you very much for your answers.

As window cleaner do you mean the isopropyl alcohol that sometimes comes in blue liquid?

I finally ended up cleaning it with "6 en 1" by GPM which is very used for many things here in Spain and it seems all stains or almost all of them have gone (I will see tomorrow more clearly). Could the blade sharpness have been affected by this product? I would swear it's a little bit duller now Maybe it's because of the previous rust or just my mind?

Excuse me my ignorance, but why other things made of stainless steel, as for example spoons that we use every day to eat, don't rust so much? I am quite sure they are completely different steels, but why don't they make knives with it then? at least the handles and clip which doesn't need to retain blade sharpness.

[jekostas]

Excuse me my ignorance, but why other things made of stainless steel, as for example spoons that we use every day to eat, don't rust so much? I am quite sure they are completely different steels, but why don't they make knives with it then? at least the handles and clip which doesn't need to retain blade sharpness.

Steels used in knives have significantly more carbon in them to make them harder.  Even the handles and clip need to be fairly stiff, otherwise the tension from usage and the locking bar would warp the handle and destroy the knife.  Besides, would you want a pocket clip that easily bent, making it much more likely for you to have your knife fall out and become lost?

[asupernothing]

Excuse me my ignorance, but why other things made of stainless steel, as for example spoons that we use every day to eat, don't rust so much? I am quite sure they are completely different steels, but why don't they make knives with it then? at least the handles and clip which doesn't need to retain blade sharpness.

Steels used in knives have significantly more carbon in them to make them harder.  Even the handles and clip need to be fairly stiff, otherwise the tension from usage and the locking bar would warp the handle and destroy the knife.  Besides, would you want a pocket clip that easily bent, making it much more likely for you to have your knife fall out and become lost?

That being said, it is common to use a "lower-end" steel for the liners/clip as jalbam said. 420J comes to mind. As jekostas said, the problem with lower end steels is that they bend far too easily, I have bent a few pocket clips and nearly lost some knives. Thats why I like titanium clips...

IMHO the staining you see can occur on any steel. As much as I would like to blame "cheap, Chinese steel" I have seen it happen even on a 154cm blade, though the CPM and other powder process metals minimize the effects...

[jzmtl]

Even 420J still have way more carbon than your spoon does.

Something else to think about, the rust may not be from "your" steel. The tooling could've been used on something else less rust resistant, and transferred some of that to your knife.

[jalbam]

Thank you very much for your comments. I still have to learn a lot about this materials, it seems a world itself!