Patent ID: 7165664

Claim:
A wet-type segmented friction material comprising: a core metal of a flat ring shape; and a friction material substrate cut into a segment shape along the flat ring shape of the core metal, thereby preparing segment pieces each having the segment shape, the segment pieces being joined by adhesion on one or both surfaces of the core metal along the flat ring shape, an area around a cut portion corresponding to the segment shape of the friction material substrate being pressed and heat-compressed at two opposite end parts as two straight lines of the cut portion when the friction material substrate is cut into the segment shape before being joined on the core metal, so that the area around the cut portion of each of the segment pieces defines a heat-compressed portion wherein components thereof are joined with each other by heating and compressing, each of said pressed and heat-compressed areas formed at the two opposite end parts of the friction material substrate being formed into a band-shaped depressed flat area extending along a side edge of an unpressed area defined between said two pressed and heat-compressed areas of the friction material substrate with an even thickness in its entirety that is smaller than a thickness of said unpressed area, each of said pressed and heat-compressed areas having a material density higher than a material density of the unpressed area.