Can 1/4" npt work on g1/4"

[Fragmet]

I was curios if 1/4" npt fitting would work on my supremacy evo waterblock that has g1/4" threading?

 

[Eximo]

G1/4" is a straight thread, and why PC fittings come with O-rings. NPT is a tapered thread that is self-sealing, but usually needs something like plumber's tape for a good seal.

You could make it work, but I doubt the experience would be pleasing or look good.