A method of forming a molded polymer part having a screw boss includes positioning a screw boss insert on a pin of a mold tool. The screw boss insert may contact guide surfaces of the mold tool. During molding, polymer material flows along the screw boss insert while the screw boss insert is positioned on the pin. The polymer material may bond to the screw boss insert. The screw boss insert may include one or more geometric features that prevent rotation and/or axial movement of the screw boss insert relative to the surrounding polymer material.