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View Full Version : Black DLC coating + stainless steel = 90RC?



Magic_Salad0892
05-20-13, 11:36
https://www.glockworx.com/products.aspx?CAT=3719

In that description it says it's about 90RC. Which is by far the hardest I've ever heard of, as Nitride is about 64RC, and a diamond is 70, from what I know.

I also know that Nitride doesn't go as well with stainless as it does with carbon type steels... but...

http://www.ar15.com/forums/t_5_13/100436_GLOCK_PIC_THREAD_PART_II.html&page=71

Scroll down to the Noveske memorial slide, where it states that it's a stainless steel slide with Black DLC. 90RC still.

Anybody that can clarify? If it's really harder, then that makes it way more ideal than nitride.

Another explanation:

IonBond DLC

IonBond DLC (stands for Diamond Like Carbon) is a hard black finish that is fairly new to the firearms market. It is a is a physical vapor deposition coating that has a 3-6 micron build up per surface (that's less than .005"). DLC can be applied to carbon steel, stainless steel, aluminum, over polished surfaces as well as matte surfaces. When bone-dry it is a dark charcoal color. With a little oil on it, it's black. It's hardness runs 70+ on the Rockwell "C" scale. I think it's the best all around option for a black firearms finish. It appears to be the equal to hard chrome in the durability and rust resistance departments. Black-T might be a better choice if rust resistance is the main criteria, like working in a salt water environment with no care given to wiping down every day or so, but in a less hostile climate or one with more care given, rust is a non-issue. There are a couple of peculiarites with DLC. It requires that the part be able to conduct an electrical charge, creating a problem in coating anodized aluminum. Anodizing is an insulator. If the aluminum is bare, it can be successfully coated with DLC. Type III hard coat anodizing might be a better choice for your aluminum frame than DLC in this respect: DLC (and hard chrome, too) is a little like an unpeeled hard-boiled egg. The exterior is fairly hard and tough, but because of the relative softness of the interior, that coating (or shell) is also a little bit brittle. Should an aluminum-framed pistol coated in such a manner be dropped and dented, the coating's adhesion with the substrate may be compromised. I don't consider that to be a huge deal. I understand that I've already made a compromise by selecting an aluminum frame to start with. I understand that aluminum is easier to dent than steel and I accept the risk. Anodizing penetrates the surface of the aluminum as well as building up the exterior. I'd recommend finishing your Lightweight Commander, for example, with Type III anodizing on the aluminum parts and DLC on the steel ones, getting the best of both worlds.


Another unique feature to know about DLC is that the shape of the part can have an impact on how the PVD process coats the part. For example, the shape of beavertail grip safeties can sometimes cause a faint, narrow "stripe" to be seen on the back side of the safety, where your hand goes. It changes appearance somewhat, due to light and the presence of oil. It is an anomaly that the IonBond people are trying to solve, but still shows up from time to time. I mention this because some guys after learning about DLC, get the idea that DLC is the modern day replacement for bluing and is superior is all regards. Well, it's not.


Bluing is a process where the parts are submerged in the salt bath and all surfaces are equally coated. The process for applying IonBond DLC requires that each part be tied to a wire that is hung from a fixturing tree after which a vacuum is drawn in the chamber and the atomized molecules are transferred through the vacuum to the negatively charged part being finished. It’s possible for a tiny speck of gray dust to land on a part at just the wrong time and a tiny white spot can occur. It’s something that IonBond works hard to avoid, but has been known to happen. If it does, the only thing that can be done is to abrasive blast the part until the finish is entirely stripped (which leaves the metal in a rough matte texture), then sand any polished surfaces back to whatever level they are supposed to be and send it back to IonBond to be recoated. IonBond will recoat the part at no charge. Were this a blued part, it could just be dipped a second time in many cases with no additional prep work. I will charge for any prep work involving sanding and any additional roll mark restoration needed. For this reason, I really recommend only doing matte IonBond finishes.


While DLC comes close to matching the appearance of bluing, it's not quite the equal in it's ability to have a consistent, uniform color, regardless of the shape of the part or the direction of the light. It also doesn't reflect light the same as bluing. It always looks a little hazy, just because it doesn’t reflect light the same way. If you're selecting a finish for your family heirloom, presentation grade pistol, where appearance is the chief concern, bluing is still the King. If you want a best of breed, black finish that excels in many areas and when durability is really important, DLC is the good stuff.

http://www.harrisoncustom.com/Static/Finishes.htm

and more here:

http://www.richterprecision.com/dlc-coatings.html

So, would a DLC type coating be better than a nitride?

bleaman225
05-20-13, 13:02
http://www.richterprecision.com/dlc-coatings.html

So, would a DLC type coating be better than a nitride?

(someone please correct me if any of this is inaccurate)

I used to work for Richter Precision in E. Pete, PA. I was one of the few maintenance mechanics there at the time. It was fun job and a great place to work. I stupidly quit and should have stuck around. Oh well, live and learn. I don't know everything about the science involved, just how to repair the machinery but...

I don't think a true comparison between HV and HRC measurements can be accurately drawn. HV is generally used to measure a thousandth or two into a case hardened surface, or other surface treatments. HRC is used to measure "deeper" into the material to find the overall hardness. You could use HRC to measure the core material and then HV to measure a coating such as DLC. (someone please correct me if any of this is inaccurate)

If you used Richter Precision Titankote C11 you would have an HV scale of 2000-3000. If you were to use a generalized conversion calculator to do the math for you...
http://www.tribology-abc.com/calculators/hardness.htm
You will find that that puts you right in the 90 HRC scale.

I don't believe that a direct comparison can be drawn to say that the slide of you gun which has been coated with C11 is now harder than a diamond.(someone please correct me if any of this is inaccurate)

With all that being said, I personally think that DLC is a much better surface treatment if done correctly and lack of proper maintenance/corrosion is not an expressed concern. I am not an expert, I just repair machinery so take it for what it's worth. And oh yeah... (someone please correct me if any of this is inaccurate)

Magic_Salad0892
05-20-13, 13:07
With all that being said, I personally think that DLC is a much better surface treatment if done correctly and lack of proper maintenance/corrosion is not an expressed concern.

What if corrosion resistence, and lack of maintenence is a factor?

Not that I don't maintain the gun, or swim in salt water. It's just curiosity right now.

bleaman225
05-20-13, 13:23
What if corrosion resistence, and lack of maintenence is a factor?

Not that I don't maintain the gun, or swim in salt water. It's just curiosity right now.

I should have worded that differently....
Even if you don't maintain your gun and swim in the ocean, I personally believe that DLC is an ideal coating for a firearm. Just know that there is a chance certain base metals may corrode as oxygen could still find it's way down there. I was just addressing the comment Harrison made about salt water environments and Walter Birdsong's coatings.

Yes the processes that are already in use out there work fine as is but I feel that DLC would be a good step forward.

Somewhere around here I still have a small custom folding knife that the blade was coated for me with Richter's DLC. I have had it for years, it even came with me for my entire 5 month Appalachian Trail thru-hike. It's been soaked in sweat (lots of sweat), went swimming in the Atlantic Ocean and Gulf of Mexico. I have never wiped it off. It's O1 tool steel underneath, it would have rusted by now if it was going to.

bleaman225
05-20-13, 13:27
Here's some good stuff on hardenss
http://www.calce.umd.edu/TSFA/Hardness_ad_.htm

And no, it's not a link to gay porn...

Magic_Salad0892
05-21-13, 04:38
Here's some good stuff on hardenss
http://www.calce.umd.edu/TSFA/Hardness_ad_.htm

And no, it's not a link to gay porn...

If it had been, it would've been funny enough for me to forgive you.

:p

Thanks for the information, man.

From what you said my understanding is that the surface (using generalized conversion math) should be around 90RC, but the metal underneath would be less. However this would ensure the steel wouldn't be brittle. Oxygen could get underneath the coating and cause rust, but probably only if the coating wasn't done correctly anyway.

Am I close?