the golf club head of the present invention includes a material , located in or around the bottom portion of the face where it meets the sole , having a higher density than that of the material used to form the remainder of the club head . this high density material is attached to the club head via welding , press fit , mechanical entrapment , bonding , fastening , or the like . a preferred embodiment of the present invention is shown in fig1 and 2 . the iron - type golf club head 10 of the present invention has a face 20 , a sole 30 extending rearwardly from a lower portion 22 of the face 20 , and a recess 40 located in region 45 spanning at least part of the lower portion 22 of the face 20 and extending into at least part of the sole 30 . this region 45 is commonly known as the leading edge or the “ chin ” of the golf club iron head . an insert 50 is affixed to the head 10 within the recess 40 via welding , press fit , mechanical entrapment , bonding , fastening , or the like . as shown in fig2 , the recess 40 has a convex bottom portion 42 and the insert 50 has a concave back portion 52 that mates with the convex bottom portion 42 and provides additional surface area for welding , bonding , and / or fastening procedures . another embodiment of the present invention is shown in fig3 . in this embodiment , the recess 40 has a longer , convex bottom portion 42 and the insert 50 has a longer concave back portion 52 for mating with the convex bottom portion 42 . a third embodiment , shown in fig4 , has a recess 40 without a convex bottom portion . instead , the recess 40 has a flat bottom surface 44 , and the insert 50 has a flat mating back surface 54 that lines up with and can be affixed to the flat surface 44 of the recess 40 . the insert 50 of the present invention is composed of a material having a density higher than that of the material of the club head 10 . the density of the material used to make the insert 50 may range from 7 g / cm 3 to 20 g / cm 3 , and preferably is 18 g / cm 3 . the head 10 preferably is made of a type of steel material , such as carbon or stainless steel , and the insert 50 preferably is made of a tungsten alloy . the recess 40 may take up the entire chin or leading edge region 45 of the golf club head 10 , extending all the way from the toe 12 of the golf club head to the heel 14 , or , as shown in fig1 , the recess 40 may extend only part of the way between the toe 12 and the heel 14 . the greater the recess 40 size is , the greater the size of the high density insert 50 , so a golfer desiring a iron having an extremely heavy chin weight would select a iron head with a recess 40 , and thus an insert 50 , extending from the furthest reaches of the toe 12 to the furthest reaches of the heel 14 within the chin region 45 . the irons of the present invention have high density leading edges and thus extremely low , forward centers of gravity and moderate loft / de - loft moments of inertia ( iyy ). the graph 100 in fig5 shows the center of gravity locations , mapped according to height and depth of the iron head frames , of 6 - irons of the present invention and 6 - irons currently available on the market . the circled region 110 in the graph indicates the center of gravity locations of irons designed according to the present invention , while the small circles represent callaway irons and the small dashes represent non - callaway irons . center of gravity locations are generally obtainable by referring to the leading edge weights of the irons . the irons of the present invention may be composed of any number of materials known in the art , including metal alloys and composites . the irons of the present invention may also take any shape or general structure known in the art , including , but not limited to , the shapes and structures disclosed in u . s . pat . nos . 5 , 626 , 530 , 5 , 749 , 795 , 6 , 769 , 998 , 7 , 083 , 531 , 7 , 338 , 387 , 7 , 338 , 389 , and 8 , 043 , 165 , the disclosure of each of which is hereby incorporated by reference in its entirety herein . from the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof , and other embodiments illustrated in the accompanying drawings , numerous changes , modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims . therefore , the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims .
a golf club iron having a head center of gravity that is low and forward enough to provide a better swing , good striking and swinging feel , and improved ball flight is disclosed . the iron has a recess in a leading edge region and a high density insert disposed within the recess to achieve the desired center of gravity location .