Use these on my license plates.
Tamper-Resistant Button-Head Socket Cap Screws find them on McMaster Carr
Difficult to remove without special tools, use these screws in public spaces to add safety and security. Length is measured from under the head. These screws are not recommended for high-strength fastening.
18-8 stainless steel screws have a minimum Rockwell hardness of B70 and a minimum tensile strength of 70,000 psi.
Black-oxide alloy steel screws have a minimum Rockwell hardness of C38 and a minimum tensile strength of 135,000 psi.
Pin-in-Torx—Use with tamper-resistant Torx drivers and bits. Thread fit is Class 3A.
Pin-in-Hex—Use with tamper-resistant hex drivers and bits. Thread fit is Class 3A.
High Security—Have a unique drive that is sold only by McMaster-Carr. Thread fit is Class 2A. Use with the driver bits sold separately.
For technical drawings and 3-D models, click on a part number.For technical drawings and 3-D models, click on a part number.