(Large hydraulic machine noises) Today, we are in one of the world's largest industrial diamond manufacturing facilities, US Synthetic, and we have special permission to see how this machine behind me manufactures genuine Mohs 10 level polycrystalline black diamonds. You might be thinking that diamonds are those shiny rocks you see in wedding bands, but in reality, about 99% of the diamonds purchased every year, about 15 billion carats' worth, are synthetic industrial diamonds. Used for crazy things like drilling thousand foot holes in the Earth or building frictionless bearings that can survive in harsh environments for decades. For example, the underwater RivGen power project in Igiugig, Alaska, uses greaseless diamond-on-diamond bearings in an underwater generator for essentially maintenance-free electricity generation. Diamonds are pretty cool. To make a diamond is actually incredibly simple while at the same time extraordinarily difficult. The first ingredient, if you're following along at home, is a baggie of monolithic diamond polishing powder, the same stuff you'd find impregnated in a diamond grinding wheel, polishing compound, or ceramic cutting saw blades. It's pretty common stuff—so common, in fact, that you can find a bag of diamond dust just like this on Amazon for about 15 bucks. In order to transform this synthetic diamond dust into a diamond large enough and strong enough to be used on a drilling rig, we have to spoon the dust into a very small metal cup about the size of a thimble. If you don't know what a thimble is, you can ask your grandma; I'm sure she would love to show you. We know that diamonds form under extreme heat and pressure, which is true, but we also need a dash of cobalt from this piece of cobalt-cemented tungsten carbide. This piece acts as a substrate for the diamond we are creating. The diamond and tungsten will bond together as it is placed under extreme pressure. I'll explain more in a second. Now that we have our ingredients secured in the thimble, the giant press is able to create two diamonds at a time using—and this is true—clean white table salt to center the two diamond molds inside a metal cylinder. US Synthetic calls this cylinder a heater. This heater is going to become the resistive electrode that brings us to 2500°F inside the diamond press. The salt is indeed Real Salt; they make these delicious internal salt supports right here in the same building. Since there are an infinite number of diamond sizes needed throughout the industry, the salt can be compacted in an infinite number of ways to support any size of diamond that fits within that resistive heater tube. The heater tube is then placed within a block of talc, also formed here at the same factory in a similar way as the salt, and circular metal contacts are placed on either end of the block. The talc will help form a gasket around the diamond when it gets placed within the six-piston cubic diamond press. The diamond press itself is monstrous. Its whole job is to focus over 1 million PSI onto the diamond mold we just assembled. If you don't happen to have one of these six-piston Megamillion PSI cubic presses at home, you can also use 2,000 elephants stacked on a Rubik's Cube, 900 school buses all parked on a Post-It note, or the equivalent of the whole Eiffel Tower placed in the palm of your hand. But remember, pressure alone is not enough. We also need heat. If you look at the top and bottom anvil inside the diamond press, you'll see a circular positive and negative contact pad which uses electricity to turn the metal canister we assembled earlier into a red-hot 2500°F resistive heating element. Diamonds take about a billion years to form in the Earth's surface, and we're trying to accomplish that exact same thing in about 10 minutes. This means that the materials that make up this press are reaching their theoretical limits of the forces that they can withstand, which is why each of the presses is hidden away in their own blast rooms with their own blast doors, just in case they experience a sudden unscheduled disassembly, which has happened in the past and will probably happen in the future. There are a lot of forces at play, but hopefully not this time. The electricity pulsing through that resistive heater is doing several things: one, helping the diamond dust to crystallize or center into one unified solid diamond, while at the same time, the heat is liquifying the cobalt inside the tungsten carbide substrate, allowing it to leach from the tungsten into the diamond to catalyze the crystallizing action. As a side effect, the cobalt also turns our diamond dust from yellow into a pitch-black color. As the new large polycrystalline diamond is created, all of that happens within just the space of about 10 minutes. As a bonus, because of the random orientation of all those individual yellow diamond crystals we started with, it means that all those small crystals are permanently interlaced and structured together like a tower of invincible, microscopically little Legos. This means the toughness of our new synthetic black diamond actually now exceeds that of a natural single-crystal clear diamond. I'm sure there's a feel-good story about how we're all stronger when we work together or something, but I'm just more impressed that we beat Mother Nature at her own game. Hot, still hot. Yeah, I should have asked. The cool part about the whole diamond mold being made from salt and talc powder means that cleanup is incredibly safe, non-toxic, and simple. We break through the compressed talc gasket, bust through the metal heater tube, and grab our diamond-filled thimble from the salty remnants, being careful not to lick any of it this time around because it probably wouldn't taste as good. The black diamonds are still permanently sealed inside the two thimbles, which means we have to blast away the casings with some silicon carbide. A silicon carbide sandblaster is a level 9 on most scales of hardness, but since the diamond we just manufactured is a legitimate 10, like my wife, it'll be unfazed and unscratched by the blasting, which is partially why having an Mohs 10 diamond tooth drill bit makes so much sense. The diamond teeth will never encounter something they can't chew through, at least here on Earth anyway, since nothing is harder than a polycrystalline diamond. The hardness, however, makes polishing rather difficult since the only thing that can cut or polish a diamond is more diamond. Luckily, the synthetic diamond dust that we started with is relatively inexpensive, and we can use a sequence of CNC polishing machines to bring the diamond to the correct dimensions. You might have noticed that this particular diamond we created is still attached to its tungsten carbide substrate. In most cases, this tungsten carbide base doubles as a mounting location for each individual tooth on the drill head, but we can also grind away the tungsten carbide base completely, leaving behind just the black diamond. That's the grind wheel that's on this machine here. We can then use that diamond disc all by itself for other things like—and this is true—high-end 3D printer nozzles. Until now, one obstacle of printing abrasive materials like ABS, carbon fiber, or glass fibers is that the more abrasive filaments will slowly sand off or wear away bits of the 3D printing nozzle as it is printing. But if you replace a normal 3D printer tip with a literal piece of solid black diamond, the hot end becomes basically invincible. I'm not allowed to show the exact process for how these 3D printer tips are made, but it's pretty incredible. It's just like bling for 3D printers, but actually more durable and prints longer than the old-school regular metal nozzles. Kind of gives the term "put a rock on it" a whole new meaning. You could say, "Diamonds are a 3D printer's best friend." This video is not sponsored, but at my wheelchair factory, we've upgraded all of our Bambu Lab printers to these DiamondBack diamond tip nozzles, so we have less maintenance, and now we're able to have a diamond printing a diamond out of some really abrasive carbon fiber filaments all without damaging the tip. Being an actual diamond means that it should be invincible to my Mohs hardness picks, which only go to a level 9. Moment of truth. It's time for a scratch test. We have our Mohs 9, and it should leave no marks on the surface because the only thing that can scratch a diamond is a diamond. There are no scratches at a level 9 and zero deeper grooves to be had. The people here at US Synthetic say we are barely scratching the surface of what diamonds are capable of, and so I'm curious, what should we make out of diamonds next? If we had a press big enough, could we make a phone case? Let me know down in the comments. And if you want to get one of the diamond tip 3D printing nozzles for yourself, I'll leave a link for those down in the description. Thanks to US Synthetic for giving me a tour of their facility, and thanks to you for watching. I'll see you around.