Hi,
Here is my procedural approach inspired by a recent blendernation post ( https://www.blendernation.com/2019/03/07/material-download-procedural-milled-metal/ )
Updated Link: https://drive.google.com/file/d/1UU5AAEWpfEfwLvoNle4QChIlug055hXd/view?usp=sharing
Hope you like it