A stud pin includes a tip including an end surface configured to come into contact with a road surface, a body portion configured to support the tip, and a lower flange. The flange profile shape of the lower flange is an anisotropic shape. The flange profile shape includes four or more first flange protrusion portions that project in the longitudinal direction and two second flange protrusion portions that project in the lateral direction. A tip profile shape of the tip is a shape including tip linear portions extending in a linear manner. At least one of the tip linear portions extends along 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.

A stud is inserted into a tread portion of a tire. The first stud includes a tip end protruding from the tread portion for contacting a surface, the tip end comprising a radially outer portion with a first surface, a second surface, a third surface, a fourth surface, a fifth surface, a sixth surface, and a seventh surface, the first surface defining an irregular quadrilateral and extending radially inward from the fourth surface toward a planar side of the tip end; and a base including a flanged bottom portion provided on an end opposite the tip end and extending radially outward, a stump portion provided between the bottom portion and the tip end, and a shank portion interconnecting the stump portion and the bottom portion, the base being embedded and secured in the tread portion of the tire in which the first stud is installed, the bottom portion having a tear-drop shape comprising three planar sides and one semi-cylindrical side.

A stud pin for mounting in a pneumatic tire includes a tip including a tip end surface configured to come into contact with a road surface, and a body portion configured to house the tip. An end surface of the tip configured to come into contact with a road surface comprises an axis of symmetry which defines a line symmetrical shape of the end surface; a centroid of a shape of the end surface offset to a first side in an axial direction from a center position of a range the end surface covers in the axial direction of the axis of symmetry; and a recessed portion recessed inward of the end surface, the recessed portion being provided on, of peripheries of the end surface, a periphery of the end surface running between a first most distal end portion and a second most distal end portion.

A method for arranging stud pins in a pneumatic tire is a method for arranging stud pins in a tread portion at intervals in a tire width direction so as to form a plurality of rows. This method includes specifying an inner region, an intermediate region, and an outer region by virtually partitioning the tread portion into equal three parts from a center line extending in a tire circumferential direction to a ground contact end in the tire width direction outward. The method also includes arranging the stud pins such that among numbers of stud pins per row in the inner region, the intermediate region, and the outer region, the number in the outer region is the largest, the number in the intermediate region is the second largest, the number in intermediate region is the smallest.

A stud pin includes a tip and a body portion provided around a center axis of the stud pin. The body portion includes an upper flange, a lower flange, and a shank portion connecting the upper flange and the lower flange. A first side surface of the lower flange includes a first curved surface recessed inward in relation to the body portion. A second side surface of the upper flange includes a second curved surface bulging toward a periphery of the body portion, and a pair of flat surfaces configured to connect the second curved surface to interpose the second curved surface. A trough portion where the first curved surface is most recessed and a peak portion where the second curved surface is most bulged are located at an identical orientation position about the center axis as viewed from the axial direction.

Disclosed is a tire stud comprising a stainless steel body with a flange and a blind hole and further comprising a spike installed in said hole, wherein the cross-sectional shape of the hole is different from the cross-sectional shape of the spike at least at one of: the opening, the lower surface of the spike, and a depth between the opening lower surface of the spike; whereby only protrusions of the spike are attached to the side wall of the hole with friction joints where the cross-sectional shape of the hole is different from the cross-sectional shape of the spike.

A stud is inserted into a tread portion of a tire. The first stud includes a tip end protruding from the tread portion for contacting a surface, the tip end comprising a radially outer portion with a first surface, a second surface, a third surface, a fourth surface, a fifth surface, a sixth surface, and a seventh surface, the first surface defining an irregular quadrilateral and extending radially inward from the fourth surface toward a planar side of the tip end; and a base including a flanged bottom portion provided on an end opposite the tip end and extending radially outward, a stump portion provided between the bottom portion and the tip end, and a shank portion interconnecting the stump portion and the bottom portion, the base being embedded and secured in the tread portion of the tire in which the first stud is installed, the bottom portion having a tear-drop shape comprising three planar sides and one semi-cylindrical side.

A stud pin and a pneumatic tire are provided. A tip portion of the stud pin includes an end surface with a concave polygonal profile shape including one recessed portion and one protrusion portion on a side opposite the recessed portion. The stud pin is mounted in a stud pin installation hole with the protrusion portion facing a leading side in a tire circumferential direction and the recessed portion face a trailing side.

A stud is configured to be inserted into a tread portion of a tire. The stud includes a tip end protruding from the tread portion for contacting a surface, and a base including a flanged bottom portion provided on an end opposite the tip end and extending radially outward, a stump portion provided between the bottom portion and the tip end, and a shank portion interconnecting the stump portion and the bottom portion. The base is embedded and secured in the tread portion of the tire in which the stud is installed. The bottom portion has a tear-drop shape consisting of three planar sides and one semi-cylindrical side. The stump portion has a polygonal shape consisting of three concave sides, two convex sides, and one planar side.

A stud pin includes a tip, 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 and a body profile shape of the body portion are anisotropic shape. The flange profile shape includes four or more first flange protrusion portions projecting toward the longitudinal direction and two second flange protrusion portions projecting toward the lateral direction. The body profile shape includes four or more first body protrusion portions projecting toward the lateral direction and two second body protrusion portions projecting toward the longitudinal direction.