Grey Torx Screw are also of normal screw quality its just a grey coating
Hardened Star Torx Screw for Milling Cutters offered are screws that come with precision design and constructed standards. These torx screw are hardened up to 50-55 HRC for wear resistance. These Torx screw are mainly used in indexable tools, such as Boring bar , Insert cutter , milling cutter ,They are precise screw for better grip of carbide inserts with pocket
