Abstract: In a set of golf iron heads, at least part of the striking face of each head is of a material selected for characteristics desired for the particular iron in the set, and at least some of the heads are multi-component heads in which at least part of the striking face area of the head comprises at least one face-piece component of material having at least one characteristic different from the rest of the head.There is also provided a multi-component golf iron head in which at least part of the striking face area of the head comprises at least one face-piece component, the face-piece component being: (a) of material selected for its surface friction and/or flexural modulus characteristics affecting the spin behavior of golf balls when struck by the head, and/or (b) of specific gravity and/or geometric configuration selected to contribute to the desired weight distribution in the head.

Abstract: In a golf ball, non-circular isodiametrical dimples provide increased efficiency of coverage of the surface of a golf ball (in comparison with the conventional circular dimples). Additionally, the aerodynamic properties of the ball are improved.The dimples have the shape of a regular isodiametrical figure with an odd number of curved sides and arcuate apices. The number of sides of the isodiametrical figure conveniently is from three to nine.

Abstract: In a set of golf iron heads, one of the components for each of the heads is a face-piece forming at least a portion of a striking face of the head, the thickness of the face-piece increasing from the toe to the heel of the head in at least one iron of the set and increasing from the heel to the toe of the head in at least one other iron of the set. Alternatively, the thickness of the face-piece increases from the top edge to the sole in at least one head of the set, and increases from the sole to the top edge in at least one other head of the set.

Abstract: A spherical golf ball (10) is provided with at least 500 dimples and 30 bald patches symmetrically disposed over the surface of the ball, the disposition of the dimples being substantially the same in each of twelve regions (11) of the surface of the sphere which are defined by projecting on to the surface the edges of a regular dodecahedron. At the mid point of each edge of the dodecahedron there is a bald patch (20, 21, 22, 23, 24). Each bald patch has the shape of a spherical rectangular dumbbell, a surface area of from 1.0 to 2.5 times the mean dimple area and does not enclose any dimple or part thereof.