Pneumatic tire for ice-bound or snow-covered road

A pneumatic tire for ice-bound or snow-covered roads, comprising:

• a tread of a block pattern including land portions each comprising a plurality of blocks partitioned by a plurality of main grooves extending in a circumferential direction of the tire and a plurality of lateral grooves extending in a width direction of the tire,
• each block being formed with a plurality of sipes extending in the width direction of the tire in a zigzag form in a plan view of the tread,
• wherein a plurality of fine grooves shallower than the sipes are formed in a tread surface of the land, and the angle of the fine grooves with the circumferential direction of the tire lies between 42 and 55 degrees inclusive,
• wherein the plurality of blocks form a plurality of block rows each comprising a plurality of blocks arranged in a row in the circumferential direction of the tire, with each block having all of the fine grooves inclined in only one direction,
• the angle of the fine grooves with the circumferential direction of the tire in at least one of the plurality of block rows being opposite to the direction of the angle of the fine grooves with the circumferential direction of the tire in each neighboring block rows,
• wherein the depth of the fine groove lies between 0.1 and 0.8 mm inclusive,
• wherein the width of the fine groove lies between 0.1 and 0.8 mm inclusive, and
• wherein the pitch of the fine grooves lies between 0.5 and 2.0 mm inclusive.