Engineered Source supplies a large number of special thread forming screws like this #10-32 X 3.72" unslotted indented hex washer head trilobular screw.  This specific part has been supplied to the same customer for over five years and is sold on a blanket purchase order basis.  It is manufactured in Taiwan using 18-8 stainless steel, passivated and waxed to our customer's specifications.