A golf club head , comprising: a first part forming a forward portion of the golf club head, the first part including a first side wall extending around the golf club head, wherein the first side wall ends at a first edge that defines an open side of the first part , and wherein a first interior surface of the first side wall has a draft angle of 0° or more, with respect to a first pulling direction as the first interior surface extends in a direction toward the first edge; and a second part forming a rearward portion of the golf club head, the second part including a second side wall extending around the golf club head, wherein the second side wall ends at a second edge that defines an open side of the second part , and wherein a second interior surface of the second side wall has a draft angle of 0° or more, with respect to a second pulling direction, as the second interior surface extends toward the second edge, wherein the first part and the second part; are engaged with one another via the first edge and the second edge to thereby form a parting line , wherein the parting line is irregular and extends completely around the golf club head between the first part and the second part ; wherein the first part and the second part are molded parts, wherein the first part comprises a portion of a crown surface, a portion of a sole surface and a portion of the side surfaces, wherein the second part comprises a portion of the crown surface, a portion of the sole surface and a portion of the side surfaces, and wherein the irregular parting line between the first part and the second part traces locations along the crown, sole, and sides of the golf club head at which the shape of the curve of the interior surface of the golf club head changes from a positive slope to a negative slope. a first part forming a forward portion of the golf club head, the first part including a first side wall extending around the golf club head, wherein the first side wall ends at a first edge that defines an open side of the first part , and wherein a first interior surface of the first side wall has a draft angle of 0° or more, with respect to a first pulling direction as the first interior surface extends in a direction toward the first edge; and a second part forming a rearward portion of the golf club head, the second part including a second side wall extending around the golf club head, wherein the second side wall ends at a second edge that defines an open side of the second part , and wherein a second interior surface of the second side wall has a draft angle of 0° or more, with respect to a second pulling direction, as the second interior surface extends toward the second edge, wherein the first part and the second part; are engaged with one another via the first edge and the second edge to thereby form a parting line , wherein the parting line is irregular and extends completely around the golf club head between the first part and the second part ; wherein the first part and the second part are molded parts, wherein the first part comprises a portion of a crown surface, a portion of a sole surface and a portion of the side surfaces, wherein the second part comprises a portion of the crown surface, a portion of the sole surface and a portion of the side surfaces, and wherein the irregular parting line between the first part and the second part traces locations along the crown, sole, and sides of the golf club head at which the shape of the curve of the interior surface of the golf club head changes from a positive slope to a negative slope. <EOS>