Abstract: A drum-type impeller for a centrifugal blower is provided with reinforcement against damage by centrifugal force at high peripheral speeds by reinforcing means such as gussets or rods running from the underside of each blade toward either or both of the hub disk and inlet ring and inserted near the attachment thereat of the trailing blade. Vortex formation at the underside of a blade inforced by a gusset is reduced by providing a notch at the point of attachment of the blade at approximately the same radial distance as the leading edge of the gusset. Vortex formation at the trailing surface of a gusset is relieved by using a double gusset with a slot between.