member 4 the anode has an interior surface 12 illustrated by the dashed line in fig1 which contacts the exterior surface 8 of the iron containing tubular member 4 preferably the contacting is brought about by casting the anode in molten form onto the tubular member and allowing solidification to occur the anode has an exterior surface 14 which is preferably except for the hereinafter described grooves generally cylindrically shaped the anode 10 thus preferably has an overall generally tubular shape the anode further is preferably beveled at each end to avoid hang ups on handling machinery the exterior surface 14 of the anode 10 is characterized by at least one generally circumferentially extending groove 16 preferably a plurality of generally circumferentially extending grooves 16 are longitudinally spaced apart along the exterior surface 14 of the anode generally speaking the anode will contain elements selected from the group consisting of zinc aluminum and magnesium to provide the iron containing tubular member with a desirable degree of cathodic protection the thickness of the anode can be varied to obtain the appropriate degree of cathodic protection without interfering with pipe laying machinery by those skilled in the art as a general rule the anode will have a maximum thickness as measured radially between the interior surface 12 of the anode and the exterior surface 14 of the anode which is in the range of from about 2 percent to about 30 percent of the distance as measured radially between a longitudinal axis 18.