Stud Pin and Studded Tire

A stud pin includes a tip, a body portion, and a lower flange. A flange profile shape of the lower flange is an anisotropic shape includes short sides and long sides of different lengths, and includes four or more first flange protrusion portions that project in the longitudinal direction parallel with the long sides and two second flange protrusion portions that project in the lateral direction parallel with the short sides. A body profile shape of the body portion is a shape including body linear portions extending in a linear manner. The body linear portions are disposed facing a portion of the flange profile shape between two adjacent protrusion portions of the first flange protrusion portion and the second flange protrusion portion along the outer circumference of the flange profile shape.