Does blade finish affect corrosion in tool steel?

[cali]

It is odd that Victorinox doesn't seem to want to tell us what blade steels they use as.

You can find it here:
https://www.victorinox.com/medias/?cont ... MyMTRkNmI1

1.4034, 1.4109, 1.4110
The last one is also used for SAK blades.

[Cadenno]

Victorinox uses X55CrMo14 (1.4110) steel. It can be seen in a National Geographic documentary.
A screen shot of a metal analyzer is shown at minute 6.38. Here is the link.
https://youtu.be/76VagpmUroE

[Dazen]

Victorinox uses stainless steel, so does it really matter whether it is polished or not. I understand that the steel they use is easier to polish than most, but outside of looks is there any other reason they polish their steels.

[Dazen]

Just that! I’ve got K390, 4V and 52100 all with Spyderco’s “Satin” finish, if that’s what it is called, and they all develop rust spots just looking at them.

Now here comes 15V with one of the best blade finishes, IMO, Spderco makes and I haven’t seen the slightest bit of corrosion yet. I’ve heard that Maxamet has a similar finish but I have don’t have any personal experience.

Does a smoother blade finish make them less susceptible to corrosion than a rougher one? Does anyone have two different finishes of the same steel?

You would need to do controlled testing to answer your question in order to see things more clearly the problem with anecdotal accounts is that it scatters the results and things that may seem very different could be the same but just different due to circumstance not because of materials.

I think you’re r one few on here that has the ability to do controlled testing of steels and finishes! So what do you say!?

[James Y]

Victorinox uses stainless steel, so does it really matter whether it is polished or not. I understand that the steel they use is easier to polish than most, but outside of looks is there any other reason they polish their steels.

Less need for maintenance. I’ve had some stainless steels start corroding in humid environments. There are also many complex moving parts in an SAK. I lived in Taiwan, which is very humid, for many years with only a single SAK for my EDC knife, and it never developed any corrosion on any of its parts.

Another thing I’ve used the larger blade on SAKs for is as a makeshift mini-mirror, even though the crinking (bending of the blade to accommodate adjacent tools) can cause some distortion in the image.

Interestingly, my Victorinox kitchen knives are not mirror-polished, but are lightly satin-finished. At least the mid-to-small-sized ones are.

Jim

[cali]

Victorinox uses stainless steel, so does it really matter whether it is polished or not.

Ever heard about Spyderco Salt line and why it's not made of martensitic "stainless steel"?

[JRinFL]

It’s been long known that highly polished steel is less prone to corrosion. A short search on the Internet will give you lots of background.

[JD Spydo]

Victorinox uses stainless steel, so does it really matter whether it is polished or not. I understand that the steel they use is easier to polish than most, but outside of looks is there any other reason they polish their steels.

Less need for maintenance. I’ve had some stainless steels start corroding in humid environments. There are also many complex moving parts in an SAK. I lived in Taiwan, which is very humid, for many years with only a single SAK for my EDC knife, and it never developed any corrosion on any of its parts.

Another thing I’ve used the larger blade on SAKs for is as a makeshift mini-mirror, even though the crinking (bending of the blade to accommodate adjacent tools) can cause some distortion in the image.

Interestingly, my Victorinox kitchen knives are not mirror-polished, but are lightly satin-finished. At least the mid-to-small-sized ones are.

Jim

Brother I beg to differ with you on that one. I personally own at least 5 Victorinox blades that have a mirror finish. Especially the blades on the Victorinox Swiss Tool and Swiss Tool X. I've even had a few of the regular Swiss Army Knives over the years that have polished blades. The one Victorinox boning knife that I use almost daily came brand new with a mirror polish on it. I've had it for over 15 years now.

It could be that their newer stuff might no longer be made that way and they might be going to satin finishes. Because the newest blade I have of theirs is one I got about 6 years ago. I have a ton of respect for Victorinox Cutlery. Between them and Frost Mora I don't think you can beat either one of them for the price you pay. Both of them put out decent quality for their modest prices. And both companies put out very practical and functional type cutlery as well.

[JD Spydo]

It’s been long known that highly polished steel is less prone to corrosion. A short search on the Internet will give you lots of background.

I totally agree with that statement. But there is one huge factor to be considered. The alloy/content of the blade steel has to be a metal that's capable of taking a high polish. S30V for instance doesn't seem to have those type of properties>> at least the few blades I own with S30V.

But there are blade steels that excel in that area. The old AUS-8 really seems to be a steel that you can shine to no end. And 440C also seems to be capable of taking a high gloss polish. But a lot of this stuff is already acknowledged I'm sure.

[James Y]

Victorinox uses stainless steel, so does it really matter whether it is polished or not. I understand that the steel they use is easier to polish than most, but outside of looks is there any other reason they polish their steels.

Less need for maintenance. I’ve had some stainless steels start corroding in humid environments. There are also many complex moving parts in an SAK. I lived in Taiwan, which is very humid, for many years with only a single SAK for my EDC knife, and it never developed any corrosion on any of its parts.

Another thing I’ve used the larger blade on SAKs for is as a makeshift mini-mirror, even though the crinking (bending of the blade to accommodate adjacent tools) can cause some distortion in the image.

Interestingly, my Victorinox kitchen knives are not mirror-polished, but are lightly satin-finished. At least the mid-to-small-sized ones are.

Jim

Brother I beg to differ with you on that one. I personally own at least 5 Victorinox blades that have a mirror finish. Especially the blades on the Victorinox Swiss Tool and Swiss Tool X. I've even had a few of the regular Swiss Army Knives over the years that have polished blades. The one Victorinox boning knife that I use almost daily came brand new with a mirror polish on it. I've had it for over 15 years now.

It could be that their newer stuff might no longer be made that way and they might be going to satin finishes. Because the newest blade I have of theirs is one I got about 6 years ago. I have a ton of respect for Victorinox Cutlery. Between them and Frost Mora I don't think you can beat either one of them for the price you pay. Both of them put out decent quality for their modest prices. And both companies put out very practical and functional type cutlery as well.

Joe,

Why beg to differ? I said that Victorinox blades are mirror-polished. Only some of my kitchen knives are satin-finished.

My late mom's old Vic pruning knife is a satin-finished, chisel-ground sheepsfoot blade.

My Swisstool and my Spirit multi-tool are all mirror-polished, as are all of my SAKs, except for the Vic Sawblades, of course.

I rechecked my 5 Vic kitchen knives, and my Santoku is mirror-polished or close to it, but my Vic paring knives, fruit knife and serrated utility kitchen knives are satin-finished. However, they are still very corrosion resistant.

I know this is getting off-topic, so I'll mention that 'stainless' means just that: Stains less. Not corrosion proof. The closest to that are H1/H2, LC200N, Vanax, and Magnacut.

As for carbon steel, I have old Ka-Bar traditional slipjoints from the '70s that never developed much corrosion on the blades, because the blades were mirror-polished. My satin-finished Schrade carbon steel pocketknives from that same time period could develop corrosion by looking at them funny.

Jim

[Deadboxhero]

Well it's no secret that a higher polish helps, heat treatment also plays a role too.

I don't think that either though will make a carbon tool steel behave exactly like a stainless steel. You can only do so much, a lot of us live in a lot of different environments so we have a patchwork of different experiences that may not reflect the true differences between person A saying the tool steel is like stainless and person B saying it rusts easy.

Spyderco certainly did an amazing finish on the CPM 15V I'm sure it certainly helps with corrosion some but not enough to make it anything stainless in caustic environments.

Just that! I’ve got K390, 4V and 52100 all with Spyderco’s “Satin” finish, if that’s what it is called, and they all develop rust spots just looking at them.

Now here comes 15V with one of the best blade finishes, IMO, Spderco makes and I haven’t seen the slightest bit of corrosion yet. I’ve heard that Maxamet has a similar finish but I have don’t have any personal experience.

Does a smoother blade finish make them less susceptible to corrosion than a rougher one? Does anyone have two different finishes of the same steel?

You would need to do controlled testing to answer your question in order to see things more clearly the problem with anecdotal accounts is that it scatters the results and things that may seem very different could be the same but just different due to circumstance not because of materials.

I think you’re r one few on here that has the ability to do controlled testing of steels and finishes! So what do you say!?

[wrdwrght]

My skeptical self says that chemistry rules over finish.

I’m thinking environmentally-reactive molecules are more abundant in steels that have been optimized for wear- and fracture-resistance.

I’m also thinking that, given the same corrosion-prone steel, the one with the mirror-finish will be slower to corrode because of less(ened) surface area.

Both thoughts are merely hypotheses. Like Shawn says, only experiments will tell.

Where’s an experimental physicist when you need one?Cliff sure was a loss.

[JD Spydo]

Victorinox uses stainless steel, so does it really matter whether it is polished or not. I understand that the steel they use is easier to polish than most, but outside of looks is there any other reason they polish their steels.

Less need for maintenance. I’ve had some stainless steels start corroding in humid environments. There are also many complex moving parts in an SAK. I lived in Taiwan, which is very humid, for many years with only a single SAK for my EDC knife, and it never developed any corrosion on any of its parts.

Another thing I’ve used the larger blade on SAKs for is as a makeshift mini-mirror, even though the crinking (bending of the blade to accommodate adjacent tools) can cause some distortion in the image.

Interestingly, my Victorinox kitchen knives are not mirror-polished, but are lightly satin-finished. At least the mid-to-small-sized ones are.

Jim

Brother I beg to differ with you on that one. I personally own at least 5 Victorinox blades that have a mirror finish. Especially the blades on the Victorinox Swiss Tool and Swiss Tool X. I've even had a few of the regular Swiss Army Knives over the years that have polished blades. The one Victorinox boning knife that I use almost daily came brand new with a mirror polish on it. I've had it for over 15 years now.

It could be that their newer stuff might no longer be made that way and they might be going to satin finishes. Because the newest blade I have of theirs is one I got about 6 years ago. I have a ton of respect for Victorinox Cutlery. Between them and Frost Mora I don't think you can beat either one of them for the price you pay. Both of them put out decent quality for their modest prices. And both companies put out very practical and functional type cutlery as well.

Joe,

Why beg to differ? I said that Victorinox blades are mirror-polished. Only some of my kitchen knives are satin-finished.

My late mom's old Vic pruning knife is a satin-finished, chisel-ground sheepsfoot blade.

My Swisstool and my Spirit multi-tool are all mirror-polished, as are all of my SAKs, except for the Vic Sawblades, of course.

I rechecked my 5 Vic kitchen knives, and my Santoku is mirror-polished or close to it, but my Vic paring knives, fruit knife and serrated utility kitchen knives are satin-finished. However, they are still very corrosion resistant.

I know this is getting off-topic, so I'll mention that 'stainless' means just that: Stains less. Not corrosion proof. The closest to that are H1/H2, LC200N, Vanax, and Magnacut.

As for carbon steel, I have old Ka-Bar traditional slipjoints from the '70s that never developed much corrosion on the blades, because the blades were mirror-polished. My satin-finished Schrade carbon steel pocketknives from that same time period could develop corrosion by looking at them funny.

Jim

Well Bro if I misunderstood or misinterpreted what you said you have my sincere apologies. Because it did not compute when I first read it. And when it comes to most blades made by the Swiss giant Victorinox I can go thumbs up on most every piece of cutlery they sell.
I also like their accessories and related items as well. I've got a Victorinox wallet in my pocket I've had since 2005. All of their items have durable quality.

[ChrisinHove]

I’ve previously mirror polished a couple of old Sabatier carbon steel kitchen knives, and their stain resistance increased noticeably as a consequence.

For general use, I wonder whether any steel surface texture would help retain any corrosion inhibitors applied?

Whether any enhanced protective effect of this would be better or worse than a polish finish would depend upon a huge number of variables, though, I guess.

[JRinFL]

My skeptical self says that chemistry rules over finish.

I’m thinking environmentally-reactive molecules are more abundant in steels that have been optimized for wear- and fracture-resistance.

I’m also thinking that, given the same corrosion-prone steel, the one with the mirror-finish will be slower to corrode because of less(ened) surface area.

Both thoughts are merely hypotheses. Like Shawn says, only experiments will tell.

Where’s an experimental physicist when you need one?Cliff sure was a loss.

Of course chemistry will rule over finish, but the polished finish has been applied for thousands of years and it wasn’t just done because of looks. Back when all steel finishes were applied laboriously by hand, there had to be a noticeable benefit beside just looking cool.

[JRinFL]

Some reference articles:

https://www.tandfonline.com/doi/abs/10. ... ode=ycst20

https://www.sciencedirect.com/science/a ... 5422011711

https://www.mdpi.com/1996-1944/15/12/4223

Many, many more are available if you want to do the search yourself.


Just three quick references using different polishing methods. The science has been done and we should not have to start all over again at zero.

[wrdwrght]

Hey Jim. I don’t know whether you were merely pivoting off me to make the larger point that there is a science for this question, or you were criticizing me for an apparent obliviousness to the scientific literature.

I will say that I was pivoting off Shawn to make the smaller point that if you want to play metallurgist, as if a metallurgical science does not exist, stop guessing, as in this thread (and many other threads). Form hypotheses, then test them in experiments…

And, yes, we should not have to start at zero, especially here.

But, beyond this forum whose interests are relatively vicarious, do we agree that the final word of any given science will never be written because someone is going form a hypothesis that prolongs the conversation? I ask the question because it’s demonstrable that any given science can become socially hidebound.

[cali]

Blade finish also affects toughness of the blade - smoother finish means less grooves, smaller grooves. Every groove is a stress riser that decreases toughness.

[JRinFL]

Hey Jim. I don’t know whether you were merely pivoting off me to make the larger point that there is a science for this question, or you were criticizing me for an apparent obliviousness to the scientific literature.

No criticism meant, just trying to make a larger point as you said.

[Evil D]

You're not going to turn 52100 into a Salt steel by polishing it, it's just mitigation. A polished blade will also be easier to polish again after staining or just easier to remove a patina from. I remember Murray Carter talking about sanding and polishing the primary blade grind as a way of both maintaining geometry and corrosion control, it would be done hand in hand on some steels/knives.