While many readers might think of “DownLoadable Content”, DLC in the tactical bubble most often refers to “Diamond-Like Carbon”. In short, it’s a carbon based coating used for blade steel which has specs that even exceed that of a natural diamond.

The problem with a term like DLC is, that it is an umbrella term that sums up different types of coating. The Wikipedia article about DLC alone lists seven different coatings which are all to be considered diamond-like coating but all have different characteristics. And that’s not counting in additives or contaminations. What they all have in common is that the coating consists of carbon. This carbon is forced into structures you can find in diamonds. Since there are two different atomic structures for diamonds there are several different mixes you can find in DLC.

Knife manufacturers usually just say “DLC” when they apply one of these coatings. The specifics might be interesting for nerds like me but it’s not so important when using the knife. Just keep in mind that you can get different results from DLC just like with a specific blade steel.

There are many reasons why knife makers apply DLC to their blades:

  • Diamond-like carbon can achieve extremely smooth surfaces. While most tactical knives won’t be given a mirror finish for camouflage reasons, smooth surfaces always greatly enhance cutting power
  • DLC is extremely resistant against abrasion, scratches and even chemical changes
  • The bonding is permanent and more or less not permeable. So they can use non-stainless steel with great cutting performance without worrying about rust or stain
  • Coated blades are way easier to clean than others

In industrial appliances DLC is used for machinery that’s exposed to massive wear. Like automatic cutters for different applications or bearings. Some DLC coatings are even certified for food processing.

Personal experience with diamond-like carbon

On a personal level I found that some of these coated blades have some excess carbon on them. Considering what I read about the coating process it might well be that the uppermost layer in fact has radically different characteristics than the rest. So you can actually rub it off with a finger. When you use a new knife with diamond-like coating it might look like the coating is wearing off very fast. You could describe it as the blade becoming a bit lighter in color. In fact it’s just the first layer and beneath it is the actual extremely resistant structure that will come through after some use. Now that I know this effect I like it like some sort of breaking in “my knife” and making it my own. It can just be a bit confusing if you’re not used to it.

Even when DLC is extremely hard and resistant it will ultimately wear off when used regularly. Especially when exposed to forces that will carve deep enough to actually scratch the steel beneath it. So while the coating will stay way longer than others it’s not a guarantee for the blade staying in perfect shape forever. This is a fact that you will have to accept and in fact many knife enthusiasts actually like a bit of a used look.