the plates with respect to the other plate wherein the material moves radially outward through a gap between the plates due to centrifugal forces created by the rotation as the material moves through the gap passing the material over bars in a refiner zone of a first one the plates each bar in the refiner zone having a leading face and an upper ridge wherein the leading face includes a sidewall of the bar facing a direction of rotation of the opposing plate and the leading edge has an interior angle of between 150 degrees to 175 degrees and discharging the material from the gap at a periphery of the refiner plates application_number US 201113243621 A description fig1 is a cross sectional view of a portion of a conventional refiner plate 10 e g a rotor or stator plate showing a conventional geometric cross sectional shape of bars 14 and grooves 12 the bars have a relatively sharp leading edge 16 formed by the intersection of the leading face 18 of the bar and the ridge 20 at the upper surface of the bar the leading face 18 is a sidewall of the bar facing the direction of rotation if on a rotor plate and facing the approaching rotor bars if on a stator plate the angle of the leading edge is defined as the interior angle 21 between.