Basics

A FDM 3D Printer Nozzle made of a Brass Body, with a Polycrystalline Diamond Insert for the Orifice / "Cone" that leads into that
Thus has:
- Higher Thermal Conductivity
- Lower Friction
- And Most Importantly: Is not impacted by Abrasive Filament (Sort of if you are printing diamond reinforced plastic!)
Better than Brass Thermal Performance, Better than Hardened Steel Nozzle / Tungsten Carbide Nozzle Hardness
Main Issue is Cost (Although in comparison to similar hardened nozzles, it is somewhat nominal)
A Bit of an Unknown is Fragility
- Due to both Impact/Shock, and if a Cold Pull (FDM 3D Printing) can be preformed
- It also has a Lead warning, need to determine if this is due to Leaded Brass or Leaded Solder
  - Either way looking into that, and Lead Exposure from FDM 3D Printing (which should be minor, but hard numbers would be nice)
It is designed in the E3D V6 Format

Comparison With Other Nozzles

Name Brand Nozzle for ~10 USD, Most 3D Printers/Hotends Come Stock with a Brass Nozzle (ie they can be Free* with the machine)
Cannot Print Abrasives
Will Need Replaced After a While (Need to determine specifically how often, FDM 3D Printer Nozzle Wear as a page on this maybe? "The 3D Print General" in [*Their Review Stated Brass Nozzles Should be Replaced Every Few Hundred Machine Hours
- Granted experiences may very with that depending on dyes (ie Silk-Finish PLA FDM 3D Printing Filament ), and what Tolerances the user is looking for (if all they print are blobby blocks, seeing a slightly more rough one may be considered nominal, rather than a sign of Nozzle Wear )

~95 USD Each
Functionally Infinite (Short of Damage) Machine Time
- Would be interesting to see a Cutaway after a Long Term Test to see if the brass "tube" part wears down and/or if that is even an issue
- Then we would need a (Brass (or Even Pure Copper!) Coated (For Screw Seal) ) All PCD Hotend!
May be able to print faster (if the Hotend is the Limiting Factor in your printer (May not be so for D3D as it stands now, definitely now so for the current Prusa machines, Currently the Limiting Factor for VORON / RatRig / VZBot 3D Printers) due to the higher heat flow allowing you to "push the filament" faster

Olsson Ruby Nozzle (Same Concept, but Poor Thermal Performance, and Decent Hardness, Also there have been reports of the Insert Becoming Dislodged, hence the fragility concern) (also seems like a marketing gimmick that it is ruby, given that Synthetic Ruby is just impure (ie more materials needed) Synthetic Sapphire )

ChampionX (The Company Behind This)'s Page on DiamondBack Nozzles
A Video by the YouTube Channel "The 3D Print General" Titled "3D Printing with DIAMOND Tip Nozzles" ( ~14 Minute Watch )
A Video by the YouTube Channel "Vector 3D" Titled "A 3D Printer Hotend Nozzle That Lasts Forever?" ( ~7.5 Minute Watch )
A Video by the YouTube Channel "Robert Cowan" Titled "Is a $100 Diamond Nozzle Worth it?" ( ~9 Minute Watch )
A Video by the YouTube Channel "3D Musketeers" Titled "How Good is A Diamond Nozzle?! (We tested it!)" ( ~11 Minute Watch )
A Video by the YouTube Channel "Zach Freedman" Titled "The Highly Ridiculous Over-Engineering of the Diamondback Nozzle" ( ~25 Minute Watch )
- It turns out it was developed as a solution to an in-factory problem first to an extent
- They make Diamond Cutting Inserts, and Diamond Bearings (?) (Need to look into those, supposedly for abrasive filled environments, but would almost do the literal equivalent of the phrase "chew them up and spit them out" but with any dirt/debris. Seemed a bit overblown/oversimplified, and may be for only Downhole devices like Mud Motors etc, but interesting regardless
- Anyhow PILE of 3D Printed Jigs and so on in the Work Cells
- Run ~20 Spools per week of Nylon-CF and already had experience with working with PCD