Engineered Source supplies a number of different tamper proof fastener types in a variety of materials, both standard off the shelf parts and special to print fasteners like this one way round head machine screw. These parts are 4-40 X 1/4 and were manufactured in the United States using 302 stainless steel material.
Engineered Source Inc
Supplier and Distributor of Fasteners & Related Products
Santa Ana - Orange County - Los Angeles - Inland Empire - San Diego - Southern California - Cont. United States - Mexico