How to get rid of fireflies in my metallic materials / cycles (principled bsdf) i've been working on this Project for a while now and i am struggling with fireflies all over my metallic materials, I can easily get rid of them inside Photoshop but i would like to render an animation of the scene so i need cycles to render free fireflies frames.

I've tried:
-Increasing my samples and no matter how high i go fireflies keep apearing, they even appear more one my frame has reached 4000 samples

-tweaking my material node

-deactivating my reflective caustics 

-tweaking light (scene is iluminated by an hdri, a sun lamp and 2 point lamps)

I think it may have something to do with the roughness map or maybe lightpaths or max bounces since there are a lot of reflective materials inside the scene but im not an expert in either so i cant find a solution
First try to set Strength in your Normal Map to something less. For example 0,02. If that won't do much, set Clamp Direct to 8 and Clamp Indirect to 6 in Sampling settings (image below). If that won't help either, or difference still won't be good enough, add to each metallic material on your scene Mix Shader in which mix your current setup with Transparent BSDF by Factor of Is Reflection Ray from Light Path node (also image below). Good luck.