Very small carbide metal particles on the flanks press into the screws and reduce the emission energy ideal for serial fittings reduces the grinding pressure by up to at least 13 wear at the tip is reduced which means bits have a longer life higher torques are transmitted very small carbide metal particles on the flanks press into the screws and reduce the emission energy innovative ribo non slip surface on flat slotted cross recess ph and pz special bits are included for electric