142 144 and 146 fig1 retain the fan blade 148 upon the blade iron as can be seen in fig6 and 9 a plane formed by the flange 120 if extended would converge with and intersect a plane formed by the flange 116 proximate the leading edge when considering the direction of rotation of the fan for the summer months as above described as will be seen particularly with reference to fig6 and 8 the web 114 defines an arcuate surface 150 which effectively mates with the curvature of the outer surface 152 of the rotor 70 fig5 as the outwardly extending flange 120 then continues toward the trailing edge 154 thereof the arcuate surface 150 of the web 114 fairs into a straight surface 156 formed by the rim 132 the straight surface 156 is tangential to the curved surface 150 and to the outer surface 152 of the rotor the tangential surface ends in curved tip 158 and provides a very pleasing streamlined appearance to the trailing edge of the blade iron it will now be recognized by those skilled in the art that the blade iron as provided in accordance with the principles of the present invention maybe easily substituted for the blade irons detachably secured to rotors of ceiling fans currently in use when such is done a fan blade having the construction as shown in fig1 may also be substituted for fan blades onceiling fans currently in use the end.