Pneumatic tire

A pneumatic tire comprising:

• stud pins fitted into stud pin installation holes of a tread portion of the pneumatic tire;
• the stud pins each comprising:
• a buried base portion being embedded in the tread portion of the pneumatic tire and extending in a tire radial direction;
• and
• a tip portion protruding from a road contact surface of the tread portion upon embedding of the buried base portion into the tread portion;
• the tip portion having a tip surface longer in a tire width direction than in a tire circumferential direction;
• the tip surface having a contour formed by:
• a first protrusion portion and a second protrusion portion protruding toward a first side in the tire circumferential direction;
• a first recessed portion disposed between the first protrusion portion and the second protrusion portion and recessed toward a second side opposite the first side in the tire circumferential direction;
• a third protrusion portion and a fourth protrusion portion protruding toward the second side in the tire circumferential direction;
• and
• a second recessed portion disposed between the third protrusion portion and the fourth protrusion portion and recessed toward the first side in the tire circumferential direction;
• the first recessed portion and the second recessed portion being all of recess portions by which the contour is formed, and each being formed by a pair of adjacent sides of the tip surface, the pair of adjacent sides including a side A and a side B;
• the side A inclining relative to the tire width direction at an angle greater than 0 degrees and less than 90 degrees, and the side B inclining in an opposite direction to the inclining direction of the side A relative to the tire width direction at an angle greater than 0 degrees and less than 90 degrees;
• the tip surface comprising six to ten protrusion portions protruding outward, inclusive the first to fourth protrusion portions;
• each of the first recessed portion and the second recessed portion being an intersection point of the pair of adjacent sides, in which both of the adjacent sides forming the intersection point of the first recessed portion being directed toward the second side when approaching the intersection point of the first recessed portion, and both of the adjacent sides forming the intersection point of the second recessed portion being directed toward the first side when approaching the intersection point of the second recessed portion;
• the first recessed portion and the second recessed portion lying on a same lateral position in the tire width direction;
• and
• a length on the tip surface of the tip portion in the tire circumferential direction decreasing to reach a minimum length at the lateral position of the first recessed portion and the second recessed portion, when approaching to the lateral position from both sides of the tire width direction within a region between the first protrusion portion and the second protrusion portion or a region between the third protrusion portion and the fourth protrusion portion;
• wherein the contour is formed by an outmost protrusion portion protruding outmost on one side of the tire width direction, the outmost protrusion portion being a corner that is located in a region in the tire circumferential direction between the first recessed portion and the second recessed portion, excluding both positions of the first recessed portion and the second recessed portion.