• The micro hardness is higher than the stainless steel base material, keeping good ductility beneath the hard nitrided layer (micro hardness is 800HV minimum)
• Surface finish is smoother than with chromed stems, having less friction between the stem and guide.
• Valve seat surface is harder with the nitrated layer, lasting longer
  with lead free fuels, alcohols, nitro, or other "explosive" mixes.
• Matches any kind of seats (nodular iron seats, steel powder metal seats, hard aluminum-copper seats or beryllium copper seats).
• Higher rpm engines take full advantage of all the previous features.
• The higher the engine speed the bigger the power loss due to internal engine friction! The black nitride layer reduces this power loss due to less valve-guide friction.
• The nitrided layer is adhered to the base material at a microscopic level, so it will not "flake" or bake when the valves bend due to impacts with the pistons
• The Black Nitride applies to the whole valve while the chrome coating is only applied to the stem.
• All valves are swirl polished, have stem undercut, a hardened tip and more.

Chrome (special coating used only as noted)
Widely used and known in high performance valves Only applied to stem.

Inconel Coating (where noted)
For Superior Heat Resistance.