A stud pin includes a tip including an end surface that comes into contact with a road surface, a body portion that supports the tip; and a lower flange connected to the body portion at an end on an opposite side to the end surface. A profile shape of the lower flange is an anisotropic shape in which, of imaginary rectangles circumscribing the profile shape, a first smallest rectangle with the shortest side of its four sides being the shortest and/or a second smallest rectangle with the longest side of its four sides being the shortest includes short sides and long sides of different lengths. The profile shape includes four or more first protrusion portions that project in the longitudinal direction parallel with the long sides and two second protrusion portions that project in the lateral direction parallel with the short sides.