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 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.

A winter tire includes a tread portion provided with first inclined main grooves extending from a first tread edge near a tire equator, second inclined main grooves extending from a second tread edge near the tire equator, a first inner longitudinal groove connecting a pair of first inclined main grooves at the vicinity of the tire equator and a second inner longitudinal groove connecting a pair of second inclined main grooves at the vicinity of the tire equator. Each of the first inclined main grooves includes an axially first inner end portion extending along an axial direction of the tire to the second inner longitudinal groove, and each of the second inclined main grooves includes an axially second inner end portion extending along the axial direction of the tire to the first inner longitudinal groove.

A stud is for improving grip of a tyre. The stud includes a body having a base flange and a second part, the second part being joined to the base flange, and a pin protruding from the second part in the longitudinal direction (Sz) of the stud. The pin is made of hard metal or ceramic. The base flange has a first cross-section having a first area. The pin has a second cross-section having a second area. A ratio of the first area to the second area is 6.5 to 21. Moreover, the pin protrudes a first height from the second part such that a ratio of the first area to the first height is 20 to 50 mm.sup.2/mm.

A tyre includes a tread having tread blocks such that grooves are arranged between the tread blocks and studs installed into at least some of the tread blocks. The tread blocks define a land portion of the tread, and an envelope surface consisting of the land portion of the tread and a sea portion. An average land ratio of the tyre defined as a ratio of total land area to total envelope area, is 55% to 78%.

A tyre includes a tread having tread blocks; a plurality of stud holes; and a plurality of studs installed in at least some of the stud holes. A constellation of the studs is such that less than two studs are in a line perpendicular to a rolling direction of the tyre. Less than two studs within an area of a footprint are in the same line parallel to the rolling direction. A distance between two adjacent studs is more than 20 mm.

A tyre (200) includes a tread (210) having tread blocks (220) with grooves (230) arranged between the tread blocks (220) and studs (100, 100a, 100b) installed into at least some of the tread blocks (220). A central region (CR) of the tread (210) is arranged between a first shoulder region (SR1) of the tread (210) and a second shoulder region (SR2) of the tread (210). At least some of the tread blocks (220) are provided with sipes (240). The tyre (200) has a first density of sipes (240) in the central region (CR), a second density of sipes (240) in the first shoulder region (SR1), and a third density of sipes (240) in the second shoulder region (SR2). The first density of sipes (240) is at least 15% greater than either or both of the second density of sipes (240) and the third density of sipes (240).

A tyre includes a tread having tread blocks such that grooves are arranged between the tread blocks and studs installed into at least some of the tread blocks. A central region of the tread is arranged between a first shoulder region of the tread and a second shoulder region of the tread. A land ratio of the central region of the tread of the tyre is 1 to 30 percentage points greater than either or both of a land ratio of the first shoulder region of the tread of the tyre and a land ratio of the second shoulder region of the tread of the tyre.

A tyre (200) includes a tread (210) and multiple studs (100) in the tread (210) such that at least pins (110) of the studs (100) are exposed on the tread (210). The tyre (200) is configured such that a load index (LI) of the tyre (200) as defined in The European Tyre and Rim Technical Organization Standards Manual (2023) table G.7 is from eighty-six to one hundred sixteen (from 86 to 116). The tyre (200) is further configured such that a road wear of the tyre (200) as measured according to the standard SFS7503:2022:en is less than the value calculatable by the polynomial formula 0.000139LI.sup.2+0.0431LI1.90.

A tyre (200) includes a tread (210) having tread blocks (220); a plurality of stud holes (250); and a plurality of studs (100) installed in at least some of the stud holes (250). Studs (100b) in a centre area (CR) of the tyre (200) have higher protrusion from a surface of the tread block (220) than studs (100a) in a shoulder area (SR1, SR2) of the tyre (200).