Iron type golf club head

1. An iron type golf club head comprising:

a face plate provided with face grooves; and

a head main body arranging the face plate on a front surface thereof, wherein

the face plate comprises a peripheral edge part firmly fixed to the head main body, and a non-supported part forming an area surrounded by the peripheral edge part and having a back surface apart from the head main body, the non-supported part having a profile shape which comprises:

a toe side edge extending substantially vertically on a toe portion,

a heel side edge extending substantially vertically on a heel portion,

a sole side edge between the toe side edge and the heel side edge on a sole portion extending substantially horizontally, and

a top side edge between the toe side edge and the heel side edge on a top portion extending in a chevron shape, and

the non-supported part satisfies the following equations (1), (2), and (3):

1.1 ≦ha/hb ≦1.6  (1);

1.1×( ha+hb )/2 ≦hc ≦1.5×( ha+hb )/2  (2);

18(mm) ≦hb ≦38 (mm)  (3)

(in which ha is a toe side height (mm) of the non-supported part at a position of an end portion of the face groove closest to the toe side,

hb is a heel side height (mm) of the non-supported part at a portion of an end portion of the face groove closest to the heel side, and

hc is an intermediate height (mm) of the non-supported portion at an intermediate position between the end portion on the toe side and the end portion on the heel side).

2. The iron type golf club head according to claim 1 , wherein a length D along the face groove between the end portion on the toe side and the end portion on the heel side is 1.2 to 2.2 times the intermediate height hc.

3. The iron type golf club head according to claim 1 or 2 , wherein a dead weight member having a large specific gravity is firmly fixed to the head main body on the toe side when viewed from the intermediate position.

4. The iron type golf club head according to claim 1 , wherein the head main body has an opening penetrating back and forth.

5. The iron type golf club head according to claim 1 , wherein the following equation is satisfied:

ha<hc.

6. The iron type golf club head according to claim 1 , wherein the head main body satisfies the following equations (4), (5) and (6):

1.1 <Ha/Hb <1.6  (4);

1.1×( Ha+Hb )/2 ≦Hc ≦1.5×( Ha+Hb )/2  (5);

Hc>Ha   (6)

(in which Ha is a toe side height (mm) of the head main body in the end portion on the toe side, Hb is a heel side height (mm) of the head main body in an end portion on the heel side, and Hc is an intermediate height (mm) of the head main body in an intermediate position between the toe side end portion and the heel side end portion).

7. The iron type golf club head according to the claim 1 , wherein a height of the non-supported part of the face plate gradually increases from the heel side height to the intermediate height and gradually decreases from the intermediate height to the toe side height.

8. The iron type golf club head according to the claim 1 , wherein the head main body comprises a support surface facing and supporting the peripheral edge part of the face plate, and

the support surface is formed as approximately fixed width and continues annularly.

9. The iron type golf club head according to claim 1 , wherein a gravity of center distance is at least 35.5mm to at most 42mm from a hosel in a plane perpendicular to the centerline of the hosel.