MagnaCut Corrosion Resistance testing thread

[Salter]

Thanks, Lance! When word started getting around about MagnaCut and its well-rounded properties, there was some mention (but little testing) of its corrosion resistance. These are the sort of results I was hoping to see. So far it's lookin' like a great salt water steel. Looking forward to seeing the galvanic test results.

[Fireman]

Magna cut might replace my favorite LC200N for edc and hard use/neglect knife steel. The extra edge retention and not much practical corrosion resistance difference will at least be a close tie to my first love super steel LC200N.

[Wartstein]

I’ve had the Magnacut Mule out on the water and stored in the torture chamber for about a week now. I pulled it out today for a thorough inspection and review. See results below and judge for yourself but I’m pretty impressed. I’ll still need several more weeks to form more concrete conclusions but initial observations are very promising.
...

This is really useful info, thanks!

I personally am actually not really concerned with corrosion (VG10 / S30V... are practically totally rustproof in my use), but I do like Salt knives for other reasons (general design, very light and linerless), and Magnacut would increase their performance when it comes to edge holding.
Your results so far make clear, that probably more Salt knives could easily come in MC and still 100% fulfill the "salt standards".

Your Waterway honestly is my favorite utility fixed blade both in use and carry, and though it works perfectly well in LC, in MC it would be even better.
.... and an FRN Siren in MC would not be a bad thing at all...

[Doc Dan]

Great video with good explanations, Lance.

I wonder if the Waterway and Siren will get the Magnacut treatment? An increase in edge retention on a knife such as the Waterway can only be a good thing.

[sal]

Nice work Lance. My salt water testing has been pretty much the same. Any odd discoloration was the result of a contaminant and wiped right off.

sal

[James Y]

Would screws holding the scales to a Magnacut fixed blade be best if they were also made from Magnacut, to lessen the possibility of galvanic corrosion? Or would that even be possible?

Jim

[Evil D]

Would screws holding the scales to a Magnacut fixed blade be best if they were also made from Magnacut, to lessen the possibility of galvanic corrosion? Or would that even be possible?

Jim

I could be misremembering this but I thought all the components of the Caribbean were LC200N, and if that's true they still ended up needing to be coated.

[RamZar]

I’ve had the Magnacut Mule out on the water and stored in the torture chamber for about a week now. I pulled it out today for a thorough inspection and review. See results below and judge for yourself but I’m pretty impressed. I’ll still need several more weeks to form more concrete conclusions but initial observations are very promising.

Regarding corrosion resistance, you mentioned that so far MagnaCut has performed better than any stainless steel you’ve ever tested except for H1. In terms of just corrosion resistance, are you ranking H1 at the top followed by MagnaCut and then LC200N? Perhaps your preference of MagnaCut over LC200N also considers its better edge retention?

[RamZar]

There was a case in July 2020 of an Autonomy 2 with LC200N Satin blade having heavy rust under the manual safety lock where it impeded the use of the safety lock but not the overall function of the auto. The OP in that thread (see link below) said: “For the last 3 months since the middle of March, this knife has been in the gulf of Mexico shark fishing off the surf for about 4 hours a day every single day in my shorts pocket.”

I think Spyderco ended up coating the hardware on that model?

viewtopic.php?t=87072

I have a folder from another company which went to extreme corrosion resistance on ALL the parts (not just the blade) and it’s incredible. Here are its specs:

• Blade Length: 2.98 inches
• Blade Thickness: .090 inches
• Body Length: 3.94 inches
• Open Length: 6.94 inches
• Blade Type: Drop Point (Stonewashed)
• Blade Grind: Flat
• Blade Steel: Vanax SuperClean
• Body Type: 6AL 4V Titanium
• Hardware: 6AL 4V Titanium (T8)
• Pivot: 6AL 4V & SST
• Lock: Frame lock
• Pocket Clip: Tip-up marine SST
• Lock bar insert: LC200N/Z-FiNit
• Detent: Ceramic
• Washers: Phosphor bronze
• Weight: 2.6 oz internal milling

[Surfingringo]

I’ve had the Magnacut Mule out on the water and stored in the torture chamber for about a week now. I pulled it out today for a thorough inspection and review. See results below and judge for yourself but I’m pretty impressed. I’ll still need several more weeks to form more concrete conclusions but initial observations are very promising.

Regarding corrosion resistance, you mentioned that so far MagnaCut has performed better than any stainless steel you’ve ever tested except for H1. In terms of just corrosion resistance, are you ranking H1 at the top followed by MagnaCut and then LC200N? Perhaps your preference of MagnaCut over LC200N also considers its better edge retention?

Hey Ramzar, I actually made an error of omission in that video. I should have included Vanax, which in my testing performed VERY close to LC200N in corrosion resistance. As far as comparing Magnacut to those two, I don’t have enough time with it to say yet. I think I will be able to rank it compared to those two in another month or so.

I am heading to the US for a visit this week. I will leave the mule in the torture chamber but when I get back I want to do some side by side testing with lc200n and Magnacut for galvanic corrosion. I’ve got a couple of ideas about how to test this and it should make for an interesting comparison.

[metaphoricalsimile]

Gringo, it would be interesting if you would use a control sample alongside your test sample. Without a control, we don't have good context for how much corrosion this treatment causes in other materials.

[RamZar]

I’ve had the Magnacut Mule out on the water and stored in the torture chamber for about a week now. I pulled it out today for a thorough inspection and review. See results below and judge for yourself but I’m pretty impressed. I’ll still need several more weeks to form more concrete conclusions but initial observations are very promising.

Regarding corrosion resistance, you mentioned that so far MagnaCut has performed better than any stainless steel you’ve ever tested except for H1. In terms of just corrosion resistance, are you ranking H1 at the top followed by MagnaCut and then LC200N? Perhaps your preference of MagnaCut over LC200N also considers its better edge retention?

Hey Ramzar, I actually made an error of omission in that video. I should have included Vanax, which in my testing performed VERY close to LC200N in corrosion resistance. As far as comparing Magnacut to those two, I don’t have enough time with it to say yet. I think I will be able to rank it compared to those two in another month or so.

I am heading to the US for a visit this week. I will leave the mule in the torture chamber but when I get back I want to do some side by side testing with lc200n and Magnacut for galvanic corrosion. I’ve got a couple of ideas about how to test this and it should make for an interesting comparison.

Excellent!

[RamZar]

Gringo, it would be interesting if you would use a control sample alongside your test sample. Without a control, we don't have good context for how much corrosion this treatment causes in other materials.

That’d be nice. For instance: 20CV, S30V, VG-10.

[Crox]

I’m not an expert, but I’ve had to consider galvanic corrosion in my day job. Instead of regurgitation here is a brief explanation:

https://www.zipfastener.com/default/*** ... -Chart.pdf

With that, I’d be surprised if two stainless steels corroded each other. Additionally, most knives would spend most of their lives dry. Has there been any hard evidence of galvanic corrosion happening on a knife? What’s next - an anode backspacer?

[Deadboxhero]

I’m not an expert, but I’ve had to consider galvanic corrosion in my day job. Instead of regurgitation here is a brief explanation:

https://www.zipfastener.com/default/*** ... -Chart.pdf

With that, I’d be surprised if two stainless steels corroded each other. Additionally, most knives would spend most of their lives dry. Has there been any hard evidence of galvanic corrosion happening on a knife? What’s next - an anode backspacer?

There is plenty,

it's the reason why hard chrome coating on a blade is not the best.

It accelerated the corrosion at the edge.

Years before MagnaCut came out I thought it would be interesting to hard Chrome CPM 4V since 4V has such excellent properties except it's not corrosion resistant.

Well, the hard chrome made the edge more susceptible to rusting.

It was also a problem some of the old gerber knives that had hard chrome coatings on the blades in M2 and Vascowear steel.

[James Y]

Would screws holding the scales to a Magnacut fixed blade be best if they were also made from Magnacut, to lessen the possibility of galvanic corrosion? Or would that even be possible?

Jim

I could be misremembering this but I thought all the components of the Caribbean were LC200N, and if that's true they still ended up needing to be coated.

Interesting, thanks. I do remember reading somewhere (maybe the Spyderco forum on BF) that the Caribbean’s liners were LC200N, but I hadn’t heard that the other parts (screws, etc.) were supposed to be, too.

Jim

[Crox]

…. hard Chrome CPM 4V since 4V has such excellent properties except it's not corrosion resistant.

Interesting. Though in that case not a stainless so that probably made the 4V sacrificial - closer to the mild steel on the chart or something?

Will be interesting on Magnacut.

[Surfingringo]

I’m not an expert, but I’ve had to consider galvanic corrosion in my day job. Instead of regurgitation here is a brief explanation:

https://www.zipfastener.com/default/*** ... -Chart.pdf

With that, I’d be surprised if two stainless steels corroded each other. Additionally, most knives would spend most of their lives dry. Has there been any hard evidence of galvanic corrosion happening on a knife? What’s next - an anode backspacer?

Hey Crox, it happens and it doesn’t really take that much to make it happen. If I drop a knife with lc200n blade and standard stainless hardware in the “torture chamber” the hardware will start to bleed some small amounts of rust within a couple of weeks. When it contacts the lc200n (or Vanax or other stainless steel) it will create a reaction and will cause some degree of corrosion on the lc200n that would not have otherwise occurred had it not been in contact with the hardware. This is the reason that Spyderco is now coating the hardware on their salt knives. I would agree with you that the vast majority of knife users would never be in an environment to create this type of reaction but it definitely can happen. Spyderco takes their Salt knives pretty seriously and is always going the extra mile to make them as truly rust proof as a knife can be.

[Crox]

Hey Crox, it happens and it doesn’t really take that much to make it happen. If I drop a knife with lc200n blade and standard stainless hardware in the “torture chamber” the hardware will start to bleed some small amounts of rust within a couple of weeks. When it contacts the lc200n (or Vanax or other stainless steel) it will create a reaction and will cause some degree of corrosion on the lc200n that would not have otherwise occurred had it not been in contact with the hardware. This is the reason that Spyderco is now coating the hardware on their salt knives. I would agree with you that the vast majority of knife users would never be in an environment to create this type of reaction but it definitely can happen. Spyderco takes their Salt knives pretty seriously and is always going the extra mile to make them as truly rust proof as a knife can be.

Gringo,
Thanks - this is super interesting. I might have to dig deeper into the elements of each steel to try and understand it. Do we know what standard Spyderco hardware is? 304 stainless?

[sal]

Thanx Lance.

Hi Crox,

Spyderco is constantly testing corrosion in any possible situation. That's how we learn and improve. Coming out with a production knife that will reliably work for the user in salt water environments, as not an easy endeavor. Gail and I sought that solution for decades before making it available to you. We had to kiss a lot of toads. Now that we have many years of lab testing and Real-World-Testing and we are pleased to be able to serve you with our solutions.

sal