An iron golf club and a set of iron golf clubs that have a variable weight distribution. Each iron golf club head has a cavity and a raised wall portion that extends upward from the sole and offset from the cavity. The raised wall portion is separated from the cavity by a groove set at an oblique angle to the face portion of the iron golf club The groove deepens the center of mass depth and lengthens the effective face length of the iron golf club. The width of the groove may vary between each golf club in a set of iron golf clubs, such that the width of the groove of the long irons is greater that the width of the groove of the middle irons, and the width of the groove of the middle irons is greater than the width of the groove of the short irons.