I recommend using "Linking" method for bringing screws to the scene. This method makes viewport work better and allows for faster rendering.
For linking screws in Blender:
File ••••• Link •••• Open file screw_heads_kit.blend ••••• Group ••••• pick your screw type from S1-20
If you want to change the material faster for linked screws, use addon “Edit Linked Library”.
Before adding screws to the scene, look for the file SCREW_HEADS_KIT_NUMBER_MAP.jpg for the exact screw number.