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.

A stud pin includes a tip including a tip end surface configured to come into contact with a road surface and a trunk portion that supports the tip and extends in one direction. The trunk portion includes an upper flange disposed at a first end of the trunk portion, the tip being fixed to the upper flange, and a lower flange disposed at a position to a side opposite the upper flange of the trunk portion. An upper end surface of the upper flange from which the tip protrudes includes a recessed surface, the recessed surface including a smooth inclined surface recessing in a curved manner or a linear manner toward the lower flange with advancement toward a protruding base portion of the tip.

A studded tire includes stud pins embedded in a road contact surface of a tread portion 1; the rubber composition forming the tread portion containing at least one of natural rubber, styrene-butadiene rubber, and butadiene rubber, from 5 to 50 parts by weight of carbon black and from 5 to 70 parts by weight of silica per 100 parts by weight of the diene rubber; a nitrogen adsorption specific surface area of the carbon black being from 50 to 120 m.sup.2/g; a CTAB specific surface area of the silica being from 80 to 190 m.sup.2/g; a rubber hardness of the rubber composition being not greater than 60; and a product of a stress at the time of 400% elongation and a bottom surface area of a flange portion on a bottom side of the stud pins being not less than 400 MPa.Math.mm.sup.2 and not greater than 850 MPa.Math.mm.sup.2.

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.

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.

The present invention provides a stud and tool to remove the same.

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 pin includes a buried base portion embedded in a tread portion of a pneumatic tire and a tip portion protruding from the road contact surface of the tread portion when the buried base portion is embedded in the tread portion. A tip surface of the tip portion includes: a first protrusion portion and a second protrusion portion longer in the tire width direction than in the tire circumferential direction and protruding toward one side in the tire circumferential direction; a first recessed portion disposed between the first and second protrusion portions and recessed toward the other side in the tire circumferential direction; a third protrusion portion and a fourth protrusion portion protruding toward the other side in the tire circumferential direction; and a second recessed portion disposed between the third and fourth protrusion portions and recessed toward the one side in the tire circumferential direction.

A stud pin fitted into a tread portion of a pneumatic tire comprises a buried base portion extending in a direction, the buried base portion securing the stud pin in the tread portion by being pressed by a side surface of the stud pin installation hole upon the stud pin being embedded in the stud pin installation hole, and a tip portion connected to an end portion of the buried base portion in the extending direction, the tip portion protruding past the tread portion and coming into contact with a road surface upon the buried base portion being embedded in the stud pin installation hole. A connection portion of the tip portion with the buried base portion has a cross-sectional area in a plane orthogonal to the extending direction of the buried base portion greater than an area of the tip end surface.

A removable tire stud of the present disclosure provides a stud and tool to remove the same. The removable tire stud includes a solid hexagonal shaped head portion having a top surface, the head portion being continuous with a shank portion. The shank portion including an unthreaded neck proximal to the head and a threaded portion with a blunt tip. The thread extends from the blunt tip to the unthreaded neck, and a first portion of the thread is sharpened to cut through rubber of a tire. A notched flange is fixed to the head portion proximal to the shank portion. The notched flange has two diametrically opposed notches in an outer edge thereof, and each notch is centered on a vertex of the hexagonal shaped head.