Does blade finish affect corrosion in tool steel?

[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?

[VashHash]

Case knives usually have a mirror finish and they don't rust as bad. Bead blast usually rust the most in my experience. On the southfork spyderco used a coarse satin finish and it would rust a little. I usually could scratch it off with a fingernail. The S90V military I have has never had any rust spots and it's a finer satin finish.

[abbazaba]

I had the same observation with the Police 4 G10 K390 and it's deep grinds vs Maxamet in stonewash... The smoother finish wipes clean easier and doesn't attract corrosion as quickly IME.

[Fireman]

The answer is, yes. Mirror polish will do better than textured surfaces

[Bill1170]

What Fireman said. The higher the polish, the less deep the micro crevices where corrosion tends to begin. I mirror polished two ZDP Spyderco’s and they resist rust better than they did with the factory satin finish.

[JD Spydo]

Yes it does seem that way for sure. Also there are a few blade steels that seem to polish considerably easier than others for whatever reason that might be. Take AUS-8 for instance. Sure it's an older and somewhat antiquated blade steel compared to many of the newer so-called Supersteels that we've been blessed with in the past 10 years or so>> but for culinary type blades it was good.

Also when you compare VG-10 to it's American counterpart S30V it's not even close. Sometimes the properties of certain blade steels are so obvious.

[Deadboxhero]

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.

[Evil D]

The smoother the finish, the smaller it is and the less crevices for corrosion to form. This is why you'll see everything Victorinox makes coming with a mirror polish.

[Dazen]

Seems Spyderco might already know this with their testing. But if everyone is correct in saying the more polished the blade the more corrosion resistant it is, then why not give every Spyderco made in a tool steel a fighting chance with a smoother finish?!

[Wandering_About]

Seems Spyderco might already know this with their testing. But if everyone is correct in saying the more polished the blade the more corrosion resistant it is, then why not give every Spyderco made in a tool steel a fighting chance with a smoother finish?!

Cost, especially on the high wear resistance steels.

[RustyIron]

All my knives are stone washed, brushed, and patina'ed.
Only a pimp from a cheap New Orleans wh***house would carry a mirror-polished blade.

[Evil D]

Seems Spyderco might already know this with their testing. But if everyone is correct in saying the more polished the blade the more corrosion resistant it is, then why not give every Spyderco made in a tool steel a fighting chance with a smoother finish?!

Cost, and because people would lose their minds with how scratched up their blades would get because all the scratches would show.

[WyoJon]

Ive had more than one blade maker tell me polishing helps to seal off the grain structure of steel. They claim it not only reduces surface area and improves corrosion resistance, but will improve the strength of the steel due to not having jagged varianced at the end of the grain.

Never tested the strength part myself, these were from people who were passing the american blade smith society knife tests.

I have found polished steel rusts less, and is easier to remove rust from. The oil known as ballistol is your friend. I use it to suspend the herbs yellow stone stropping compound on my pasted strop. Works oil into my finished edge as I finish it.

[WyoJon]

Seems Spyderco might already know this with their testing. But if everyone is correct in saying the more polished the blade the more corrosion resistant it is, then why not give every Spyderco made in a tool steel a fighting chance with a smoother finish?!

Cost, and because people would lose their minds with how scratched up their blades would get because all the scratches would show.

A lot of tool steels take a long time to put a fine polish on. Especially these carbide impregnated high wear resistance steels we have commonly now days. You have to cut through those carbide particles to get a perfect mirror, not just the steel matrix around them. And a lot of the finishing abrasive grits used on steel cut really slow through carbides. Which gives an uneven surface when polishing at high speeds as they will strip the steel matrix back faster leaving carbide protrusions.

[VashHash]

All my knives are stone washed, brushed, and patina'ed.
Only a pimp from a cheap New Orleans wh***house would carry a mirror-polished blade.

Okay Patton.

[Dazen]

I didn’t mean to imply I want Spyderco to polish their blades, nor would I ever buy a fully polish knife. I meant the smoother finish that is on the new 15V, which in all reality didn’t jack up the price that high for a steel that hard. I don’t know what Spyderco calls the finish but I have a 3V Hinderer with a similar finish and he calls it a “working finish”. The working finish is achieved when the blade is sandblasted then stonewashed. Is this what Spyderco does as well?

I do though want to differentiate the above finishes from that found on knives like the Drunken, where the blade is indeed polished then stonewashed. This finish is amazing and I think only done in Taichung so far.

[James Y]

My G10 S30V Native 5 looks to be possibly stonewashed. Or very lightly bead-blasted. But when touching the blade surface, it's definitely smooth. It's definitely not the same as Spyderco's common satin finish, that has smooth but visible grind lines.

Jim

[James Y]

All my knives are stone washed, brushed, and patina'ed.
Only a pimp from a cheap New Orleans wh***house would carry a mirror-polished blade.

Every Victorinox SAK I've ever owned and still carry and use has mirror-polished blades. And they're excellent tools.

Jim

[JD Spydo]

The smoother the finish, the smaller it is and the less crevices for corrosion to form. This is why you'll see everything Victorinox makes coming with a mirror polish.

That is a 1000% true. However there are some blade steels like AUS-8, VG-10 and 440C just to name a few that tend to take a good polish better than most steels.

It's really making me appreciate some of these older blade steels even more. I've never quit liking AUS-8 and VG-10 because both of those blade steels not only polish up good but they are quite function for many types of cutting jobs.

[JD Spydo]

All my knives are stone washed, brushed, and patina'ed.
Only a pimp from a cheap New Orleans wh***house would carry a mirror-polished blade.

Every Victorinox SAK I've ever owned and still carry and use has mirror-polished blades. And they're excellent tools.

Jim

Yeah I've noticed that as well with several of the Victorinox blades I've owned and used over the years. It is odd that Victorinox doesn't seem to want to tell us what blade steels they use as. But I will say that every piece of cutlery they make is usually quite functional and which ever steel they use seems to polish up really nicely. They are one of the few companies that just doesn't want to share with us which blade steel they use. It seemed like Queen Cutlery was also that way all the way up to the end of their run.

But most every blade that Victorinox or Queen Cutlery all seemed to polish up really well. Glad you brought that up Jim.