These are stainless steel precision Torx screws. They are very hard to find. This model is a shallow socket head. It is unique in that it requires less socket depth to flush to the surface. These are commonly used in knife and gun making applications.
Specifications
2-56 - Socket Head
Thread Length (measured under head) = .230
Head Diameter = .140
Torx Size Required= T-8
(1 Package= 25 screws)