In an iron golf club set including at least seven iron golf clubs of the third to ninth club numbers, each moment (Mx(gf.multidot.mm)=W.times.cos .theta..times.L) of each club of the iron golf clubs is set at a range within .+-.3% of the average value Mxm of the moments of the club heads, where W(gf) is a head weight of each of the iron golf clubs, L(mm) is a distance of a center of gravity of a head from the shaft axis line along a line normal to the shaft axis line, and .theta. (.degree.) is a lie angle of each club.
In an iron club set, the lie angle of each iron club in an iron club set is selected to be 61 degrees or larger. The lie angles of the iron clubs are set at a fixed value for every type of the iron clubs including a short iron to a long iron or progressively increase in angle value from the short iron to the long iron. Further, a ratio (L/H) of the minimum height (L) of the face at the heel to the maximum height (H) of the face of the club head, progressively increase in value in going to the long irons.
A set of golf clubs wherein the club length varies between adjacent clubs in the set by at least about 0.6 inches (15.24 mm), and preferably about 0.75 inches (19 mm). Preferably, the lie angle between adjacent clubs in the set varies by greater than about 0.6 degrees, and preferably by about 0.75 degrees. More preferably, the club head weight varies between adjacent clubs in the set by at least about 8 grams, and preferably by between about 9 grams and 11 grams. The club length and lie angle of the 9-iron can approximately equivalent to the club length and lie angle of a prior art 9-iron. For a first standard set of clubs, the 1-iron has an exemplary club length of approximately 41.5 inches (105.4 mm), and the 9-iron has an exemplary club length of approximately 35.5 inches (90.17 mm). The 1-iron has an exemplary lie angle of approximately 57 degrees, while the 9-iron has an exemplary lie angle of approximately 63 degrees.
A correlated set of iron type golf clubs is designed to improve performance. The set of clubs includes a plurality of iron type golf clubs having linearly spaced lofts such that a first iron type golf club has a loft which is x degrees greater than the loft of a second iron type golf club and the second iron type golf club has a loft which is x degrees greater than a third iron type golf club and subsequent iron type golf clubs increase in loft at the same rate. The plurality of iron type golf clubs also have lengths which are linearly spaced such that a first iron type golf club has a length which is y inches less than the length of the second iron type golf club and the second iron type golf club has a length which is y inches less than the length of the third iron type golf club and subsequent iron type golf clubs decrease in length at the same rate. The set of iron type golf clubs is further designed such that the design efficiency increases as the loft of the golf clubs decreases.
