Screw and method of making same

A screw of the self-drilling and self-tapping kind for securing a first component to a second component, wherein a space encompassing a corrosive environment is defined between said first and second components, comprising;

• an elongate cylindrical shank;
• an enlarged head formed at one end of said shank;
• a drilling tip formed at the other end of said shank;
• a threaded section formed upon said shank at an axial position adjacent to said drilling tip;
• a non-threaded section of said shank being interposed between said threaded section of said shank and said head;
• a corrosion-resistant coating disposed upon said non-threaded section of said shank for protecting said non-threaded section of said shank from said corrosive environment disposed within said space defined between said first and second components and to which said non-threaded section of said shank is exposed when said screw is used to fasten said first component to said second component;
• and
• hole enlarging means disposed upon said shank of said screw at an axial location which is within the vicinity of the junction defined between said threaded and non-threaded sections of said shank and having a diametrical extent which is substantially equal to and just slightly greater than the diametrical extent of said non-threaded section of said shank for forming a hole within said first component which is enlarged with respect to an origindal hole formed within said first component by said drilling tip of said screw and which has a diameter which is substantially equal to and slightly greater than the diameter of said non-threaded section of said shank of said screw such that when said non-threaded section of said shank of said screw is passed through said enlarged hole formed within said first component, interior annular sidewall portions of said enlarged hole formed within said first component will not deleteriously affect said corrosion-resistant coating disposed upon said non-threaded section of said shank of said screw whereby said corrosion-resistant coating remains intact so as to protect said non-threaded section of said shank from said corrosive environment when said screw is used to fasten said first component to said second component and yet excessive play between said non-threaded section of said shank of said screw and said enlarged hole of said first component will not be developed.