SEGMENT TYPE FRICTION MATERIAL

PROBLEM TO BE SOLVED: To allow a lubrication amount of an ATF between frictional interfaces in environments filled with the ATF to be significantly increased by improving the shape of a segment piece.SOLUTION: A segment type friction material 1 in which a friction material cut into segment pieces 30 along a flat plate ring shape adheres to a flat plate ring shaped core metal 2 in both faces or a single face of the perimeter, and a plurality of oil grooves 40 is formed by the gap of the mutual adjacent segment pieces 30, includes a virtual reference plane WU and a virtual reference plane WD in which the mutual adjacent segment pieces 30 are cut by a trend cutting line 31 and a trend cutting line 33 slanted within the range of a slope α angle of 15°≤α≤45° to a center line L-G formed with the plurality of oil grooves 40, the slopes α of the mutual adjacent segment pieces 30 cut by the trend cutting line 31 and the trend cutting line 33 are not arranged in a straight line, and a virtual reference width W is formed therebetween.