IRON GOLF CLUB HEAD, IRON GOLF CLUB, AND IRON GOLF CLUB SET

摘要

An iron golf club head (1) comprising three principal axes of inertia (I1, I2 and I3) passing the gravity center thereof, wherein an angle theta between the axis I1 on which a moment of inertia about a principal axis of the inertia among three principal axes of inertia becomes maximum and the normal line vector (101) of a face surface (3f) passing the gravity center thereof is 10 DEG or more and 90 DEG or less.