A disc brake pad for incorporation in a disc brake assembly which is configured to receive and brake a rotor, wherein the disc brake pad is configured to be supported to a pad supporting member of a disc brake assembly so as to move in an axial direction of a rotor when the disc brake pad is incorporated in a disc brake assembly having received a rotor to be braked, the disc brake pad comprising: a lining; and a back plate, supporting a rear surface of the lining, having a projecting lug portion and a torque transfer surface at a side edge portion of the back plate which is situated at an exit side of the rotor when the disc brake pad is incorporated in a disc brake assembly having received a rotor to be braked, wherein the projecting lug portion projects towards the exit side of the rotor when the disc brake pad is incorporated in a disc brake assembly having received a rotor to be braked, the torque transfer surface is disposed at a portion of the side edge portion and is situated further radially inwards than a radially inner surface of the lug portion in a radial direction of the rotor when the disc brake pad is incorporated in a disc brake assembly having received a rotor to be braked, the projecting lug portion includes a first projecting arc-shaped surface portion which is disposed at a radially innermost portion of the radially inner surface of the lug portion in a radial direction of the rotor when the disc brake pad is incorporated in a disc brake assembly having received a rotor to be braked, characterized in that the first projecting arc-shaped surface portion of the lug portion is situated further radially inwards than an action line of a brake tangential force exerted during braking operation when the disc brake pad is incorporated in a disc brake assembly having received a rotor to be braked, the brake tangential force being exerted on a center point of a frictional surface of the lining of the brake pad and the action line being directed towards the rotor exit side, the torque transfer surface includes a projected portion at a radially outer portion of the torque transfer surface, and the projected portion is the portion of the torque transfer surface which is projected the most towards the exit side of the rotor when the disc brake pad is incorporated in a disc brake assembly having received a rotor to be braked. a lining; and a back plate, supporting a rear surface of the lining, having a projecting lug portion and a torque transfer surface at a side edge portion of the back plate which is situated at an exit side of the rotor when the disc brake pad is incorporated in a disc brake assembly having received a rotor to be braked, wherein the projecting lug portion projects towards the exit side of the rotor when the disc brake pad is incorporated in a disc brake assembly having received a rotor to be braked, the torque transfer surface is disposed at a portion of the side edge portion and is situated further radially inwards than a radially inner surface of the lug portion in a radial direction of the rotor when the disc brake pad is incorporated in a disc brake assembly having received a rotor to be braked, the projecting lug portion includes a first projecting arc-shaped surface portion which is disposed at a radially innermost portion of the radially inner surface of the lug portion in a radial direction of the rotor when the disc brake pad is incorporated in a disc brake assembly having received a rotor to be braked, characterized in that the first projecting arc-shaped surface portion of the lug portion is situated further radially inwards than an action line of a brake tangential force exerted during braking operation when the disc brake pad is incorporated in a disc brake assembly having received a rotor to be braked, the brake tangential force being exerted on a center point of a frictional surface of the lining of the brake pad and the action line being directed towards the rotor exit side, the torque transfer surface includes a projected portion at a radially outer portion of the torque transfer surface, and the projected portion is the portion of the torque transfer surface which is projected the most towards the exit side of the rotor when the disc brake pad is incorporated in a disc brake assembly having received a rotor to be braked.