Bridgestone Sports Co., Ltd.

Koki Motoyoshi

Masafumi Nishitani

Atsuo Tateno

Makoto Kubota

Hisashi Yamagishi

Wataru Ban

An iron-type golf club head has a face which has a face surface of a flat shape, and a hosel which is continuous with the face on its heel side. A shaft insertion hole is disposed in the hosel. A protrusion protruding rearward is disposed in the vicinity of the center in a toe-heel direction. A material of the golf club head is pure iron having a high purity of at least 99.8%, for instance, pure iron having a purity within a range of 99.995 to 99.9999%. The golf club head is subjected to carburizing so that carbon diffuses up to about 0.2 to 0.5 mm from the surface. A region within 0.2 mm from the face surface has a hardness of HV 300 to 600, and a region where a distance from the face surface is 0.7 mm or more has a hardness of HV 100 or lower.

Golf club head

An iron set has plural iron golf clubs, in which loft angles of heads are larger as the number is increased, each golf club including the head having a sole that includes a front sole on a front side and a rear sole adjacent to the front sole. A bounce angle &#x3b8;of the rear sole is smaller than a bounce angle &#x3b8;of the front sole, and a width Lof the rear sole in a front-rear direction is greater than or equal to a width Lof the front sole in the front-rear direction. The width Lis from 5 to 12 mm in any of the golf clubs, the bounce angle of the front sole for the number n club is greater than or equal to the bounce angle of the front sole for the number (n-1) club and greater than the bounce angle of the front sole for the number (n-2) club.

Iron set

Diamond-shaped central section defined by grooves on a face of a golf club head

Growing community of inventors

Kawasaki, Japan

Koki Motoyoshi