Pneumatic tire with belt cords comprising four steel monofilaments one or two of which are waved

A pneumatic tire comprising

• a carcass extending between bead portions of the tire, and
• a belt disposed radially outside the carcass in a tread portion of the tire,
• said belt made of cords embedded in topping rubber at an angle (.theta.) with respect to the tire equator,
• each said belt cord comprising four steel monofilaments having the same diameters (d),
• said diameter (d) being from 0.25 to 0.28 mm,
• said four steel monofilaments including one or two waved steel monofilaments (12A) and unwaved steel monofilaments (12B),
• said four steel monofilaments being compactly twisted together so as to make alternate contact portions and non-contact portions between each said waved steel monofilament (12A) and the adjacent steel monofilaments,
• the pitch of the wave of each said waved steel monofilament being 0.31 to 0.70 times the cord twist pitch,
• the buckling strength coefficient K of said belt satisfying the relationship 80<K<165, said buckling strength coefficient K being defined as the belt cord count per 5 cm width of the belt divided by sin .theta., and
• each said waved monofilament being waved three-dimensionally by coiling a straight monofilament at a small diameter, wherein the peak-to-peak wave height of each waved monofilament is from greater than 1.8 to 2.5 times the diameter (d).