This is MK8 style nozzle, it is made from a A2 Tool Steel, heat treated to 57-62 RC and plated with TwinClad XT coating. If you are working with abrasive Carbon Fiber, Stainless Steel, wood filled or any other metal filled filaments, this will greatly improve the life of your nozzle.
A2 Hardened Tool Steel Hardness: 62 HRC
Plating: TwinClad XT Wear Resistant Plating with Non-stick Composite Additive.
Plating Hardness: 65 – 67 HRC
Coefficient of friction: 0.08