as shown in fig1 and 3 - 7 , an iron - type golf club is generally designated 20 . the golf club head 20 includes a body 21 having a face 22 with a surface 23 and a plurality of grooves 25 . the body 21 is preferably composed of a material such as titanium materials , stainless steel , carpenter steel , 1020 steel , amorphous metals and the like . the material of the body 21 preferably has a density between 4 g / cm 3 and 10 g / cm 3 . such titanium materials include pure titanium and titanium alloys such as 6 - 4 titanium alloy , 6 - 22 - 22 titanium alloy , 4 - 2 titanium alloy , sp - 700 titanium alloy ( available from nippon steel of tokyo , japan ), dat 55g titanium alloy available from diado steel of tokyo , japan , ti 10 - 2 - 3 beta - c titanium alloy available from rti international metals of ohio , and the like . the body 21 is preferably manufactured through casting . alternatively , the body 21 is manufactured through forging , forming , machining , powdered metal forming , metal - injection - molding , electro - chemical milling , and the like . alternatively , the structure of the iron - type golf club is such as disclosed in helmstetter , et al ., u . s . pat . no . 5 , 776 , 010 , which is hereby incorporated by reference in its entirety . alternatively , the structure of the iron - type golf club is such as disclosed in schmidt , et al ., u . s . pat . no . 5 , 749 , 795 , which is hereby incorporated by reference in its entirety . alternatively , the structure of the iron - type golf club is such as disclosed in schmidt , et al ., u . s . pat . no . 5 , 704 , 849 , which is hereby incorporated by reference in in its entirety alternatively , the structure of the iron - type golf club is such as disclosed in blough et al ., u . s . pat . no . 5 , 921 , 869 , which is hereby incorporated by reference in its entirety . alternatively , the structure of the iron - type golf club is such as disclosed in kosmatka , u . s . pat . no . 5 , 971 , 868 , which is hereby incorporated by reference in its entirety . alternatively , the structure of the iron - type golf club is such as disclosed in kosmatka , u . s . pat . no . 6 , 045 , 455 , which is hereby incorporated by reference in its entirety . alternatively , the structure of the iron - type golf club is such as disclosed in kosmatka , u . s . pat . no . 6 , 186 , 905 , which is hereby incorporated by reference in its entirety . alternatively , the structure of the iron - type golf club is such as disclosed in erickson , et al ., u . s . pat . no . 6 , 210 , 290 , which is hereby incorporated by reference in its entirety . alternatively , the structure of the iron - type golf club is such as disclosed in reyes , et al ., u . s . pat . no . 7 , 144 , 336 , which is hereby incorporated by reference in its entirety . alternatively , the structure of the iron - type golf club is such as disclosed in deshmukh , u . s . pat . no . 7 , 112 , 148 , which is hereby incorporated by reference in its entirety . alternatively , the structure of the iron - type golf club is such as disclosed in aguinaldo , et al ., u . s . pat . no . 7 , 083 , 531 , which is hereby incorporated by reference in its entirety . alternatively , the structure of the iron - type golf club is such as disclosed in wieland , et al ., u . s . pat . no . 7 , 338 , 389 , which is hereby incorporated by reference in its entirety . alternatively , the structure of the iron - type golf club is such as disclosed in nycum , et al ., u . s . pat . no . 7 , 338 , 387 , which is hereby incorporated by reference in its entirety . alternatively , the structure of the iron - type golf club is such as disclosed in holt , et al ., u . s . pat . no . 7 , 326 , 126 , which is hereby incorporated by reference in its entirety as shown in fig8 and 9 , the detail features are such that they are preferably contained within a zone between a circle of radius 0 . 010 inch and a concentric circle of radius 0 . 011 inch . as shown in fig1 , radius , r 1 = 0 . 010 inch , length , l 2 = 0 . 004 inch and angle θ1 = 7 degrees . as shown in fig1 , radius r 2 = 0 . 002 inch , radius r 3 = 0 . 002 inch and length l 2 = 0 . 004 inch . as shown in fig1 , length l 2 = 0 . 004 inch , and length l 1 = 0 . 005 inch . as shown in fig1 , l 3 = 0 . 003 inch , length l 4 = 0 . 005 inch , angle θ1 = 7 degrees , angle θ2 = 14 degrees , angle θ3 = 50 degrees . 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 .