Spyderco Forums

Why no DLC on more carbon steel knives?
I have a PM2 in S30V with DLC and from what I understand S30V is already pretty corrosion resistant.
Wouldn't DLC be better suited for high carbon blades?

Is there something about carbon steels that interfere with the coating process?

Possibly demand is the reason. The recent BHQ exclusives have some DLC M4 blades, however in the knife market it seems non coated models sell more than coated. I’d guess the bottom line is the deciding factor over others.

illacky wrote: ↑

Mon Jun 18, 2018 7:20 am

Possibly demand is the reason. The recent BHQ exclusives have some DLC M4 blades, however in the knife market it seems non coated models sell more than coated. I’d guess the bottom line is the deciding factor over others.

Maybe. But in another post here at this very moment there's a person asking what OTC coating is best for his Maxamet knife to prevent corrosion.
There has to be demand for it.

Hi Spydermane,

There is still argument over whether or not coatings help with corrosion resistance. Some feel that it does protect the non stainless blade and others feel that moisture seeps in and causes corrosion underneath the coating (which one cannot see) and it is not obvious unti the corrosion gets so bad it breaks through the coating and then the blade is pitted too much to clean.

Probably a good subject for discussion here?

sal

I've heard it both ways, that corrosion can get under DLC and others say DLC bonds to the metal and this can't happen. I say we coat a blade and drop it in the ocean and see what happens.

I was thinking it might be a good project for Larrin?

sal

My concern is that even with thorough testing it may be something that takes several years to show itself and by then the damage is irreversible. At least with non coated blades I can see what's happening and take steps to prevent it and polish as needed.

I'm definitely a fan of coated carbon steels. I've seen good results on their corrosion resistance out of the box.

The parts where corrosion might be a bigger problem is in the pivots where you can't see and where there usually isn't any dlc coating. I have a 52100 dlc coated manix2 I don't like to get wet. And worse is the pinned Maxamet that you won't ever know how it looks inside.

I like it as an option. I haven't used any of my DLC blades long enough to see any issues. I just like the way it looks on certain knives. I think the BHQ Manix with DLC is one of the best looking knives I have ever seen. The contrast of the black blade and hardware against the Jade scales is incredible. When they did the PM2 in DLC they didn't do the liners for some reason and it didn't look at nice as the Manix did with the black liners. I also really like my Cutlery Shopped Native 5 LW in S90 DLC and orange FRN. The black Salts with the black "DLC-like" coating are nice looking as well. I have a mixture of both coated and uncoated, and I have no real preference other than looks. My next knife purchase is probably going to be the gray Manix exclusive with the DLC 52100 blade.

I REALLY like the stonewash finish on the Maxamet Native LW, so I was super excited to hear Sal say they were going to do a stonewash on the blade of the upcoming Shaman Micarta Cruwear knife!

"My next knife purchase is probably going to be the gray Manix exclusive with the DLC 52100."

I wasn't aware of this!
that sounds like something I'd be interested in

Spydermane wrote: ↑

Mon Jun 18, 2018 9:04 am

"My next knife purchase is probably going to be the gray Manix exclusive with the DLC 52100."

I wasn't aware of this!
that sounds like something I'd be interested in

It's a beautiful knife. The all black hardware and liners makes this knife visually speaking.

Darth_cholo wrote: ↑

Mon Jun 18, 2018 9:35 am

Spydermane wrote: ↑

Mon Jun 18, 2018 9:04 am

"My next knife purchase is probably going to be the gray Manix exclusive with the DLC 52100."

It's a beautiful knife. The all black hardware and liners makes this knife visually speaking.

Definitely agree. It's the most "beautiful" of my working knives, by a long way.

sal wrote: ↑

Mon Jun 18, 2018 8:22 am

Hi Spydermane,

There is still argument over whether or not coatings help with corrosion resistance.

That is absolutely mind boggling to me.

I EDC'd a DLC Para 2 for a few years. I'd carry it IWB often. My sweat would corrode a satin finished Para 2 within 24 hours and I know this for a fact.

After 4 years of carry and use as my work knife, the blade was corrosion free on that Para 2.

Same story for all my other DLC Spydercos. Rusted the ricasso area of my C95 Manix, but my DLC Manix XL is rust free on the blade.

I've worn off the coatings of numerous fixed blades. They were all corrosion free underneath, but then developed corrosion after the coating had worn off. These were much less durable coatings than Spydercos DLC, and much less corrosion resistant steels to begin with (S7, 1095, etc.)

I don't understand how this is something folks consider debatable. The evidence is crystal clear for me. It's crazy to me that anyone questions this.

Back to the OP, I wish we'd see more coated carbon blades. Police 4 is a perfect candidate.

Evil D wrote: ↑

Mon Jun 18, 2018 8:30 am

My concern is that even with thorough testing it may be something that takes several years to show itself and by then the damage is irreversible. At least with non coated blades I can see what's happening and take steps to prevent it and polish as needed.

I've been testing this very subject for years and I can tell you my experience is 100% that they drastically improve corrosion resistance.

I've worn through various coatings on easy to rust carbon steel blades. I've also stripped some with chemical strippers or sandpaper. I've extensively used carbon steel choppers with half their coating worn off. I have never, not once, seen corrosion under a coating, nor have I ever heard of this happening in my twenty plus years of knife forum participation.

What is this idea being based on? How did this idea get started? Is there any evidence this actually happens?

Somewhat related... Out of curiosity and neglect, I left a Kershaw Cryo outside completely exposed on the patio table through an entire New England winter and there is not a spot of rust on it, despite being an all steel knife. It has a titanium carbo-nitride coating.

I'm interested to see how that DLC 52100 holds up. I've been doing my best to beat on my DLC M4 PM2 and haven't had any signs of corrosion yet after lots of food and yard work. I basically tried to destroy a standard S30v DLC PM2 last year during camping season and can still make it look almost new with some Flitz. It was the knife converted me to a DLC fan.

abbazaba wrote: ↑

Mon Jun 18, 2018 10:12 am

Somewhat related... Out of curiosity and neglect, I left a Kershaw Cryo outside completely exposed on the patio table through an entire New England winter and there is not a spot of rust on it, despite being an all steel knife. It has a titanium carbo-nitride coating.

I'm interested to see how that DLC 52100 holds up. I've been doing my best to beat on my DLC M4 PM2 and haven't had any signs of corrosion yet after lots of food and yard work. I basically tried to destroy a standard S30v DLC PM2 last year during camping season and can still make it look almost new with some Flitz. It was the knife converted me to a DLC fan.

Similar story here. Local shop had the DLC PM2 but no satin finished, so I figured I'd try it out and trade it for a satin finished version if I didn't like it. Now I wish every model had a DLC option, especially with coated liners too like the Manix XL.

Would corrosion under DLC be about as likely as corrosion between laminated steels? HAP40 and SUS410, for example?

Vivi wrote: ↑

Mon Jun 18, 2018 10:10 am

What is this idea being based on? How did this idea get started? Is there any evidence this actually happens?

Ya know that's a fair question, as I've never seen it or experienced it myself. I've used everything from ESEE's coating, which honestly doesn't seem like anything special to me, to Spyderco's DLC (though I can't really say much on that as I've only owned stainless blades coated with DLC). All I know is it has been mentioned here several times by people who would seem to know what they're talking about. This is why I would like to see some very aggressive testing done.

Some knives look great with DLC, like my 52100 Manix 2.

But, I wouldn't lose any sleep if they got rid of DLC all together.
I just prefer satin blades. I'm so happy they didn't DLC the Native 5 Salt.

Sal, any info on the N5S you can dangle over heads would be great!