A golf ball has a core, an inner cover, an outer cover, and dimples, and satisfies the following mathematical formulas.

Vw=54+0.01(2.5AB+5Cv)58.0

0.08X.sup.24.25X+34520D0.08X.sup.24.25X+345+20

A: a compression of the golf ball

B: a hardness difference between a surface and a center of the core

Cv:(HiTi+HoTo)/(Ti+To)

Cs:(HiTi+2HoTo)/(Ti+2To)

D: a total volume of the dimples

X:Sw/Vw

Hi: a hardness of the inner cover

Ho: a hardness of the outer cover

Ti: a thickness of the inner cover

To: a thickness of the outer cover

Sw: 3000+10(AB1.5Cs)

An object of the present invention is to provide a golf ball having a low spin rate on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein the spherical core is formed from a rubber composition containing (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator, and (d) a RAFT agent, (b) the co-crosslinking agent contains an ,-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof, and (d) the RAFT agent is a compound represented by the formula (1):

##STR00001## in the formula (1), R represents a monovalent organic group, and Z represents a monovalent organic group.

Disclosed herein are golf balls having a thermoplastic outer cover layer formed from a thermoplastic polyurethane composition. The golf balls are produced without the use of a secondary treatment step that would result in the crosslinking of the polyurethane cover composition.

Multi-piece golf balls having a multi-layered solid core and multi-layered cover are provided.

Golf balls comprising a multi-layer core and a cover are disclosed. The multi-layer core comprises a center, an intermediate core layer, and an outer core layer. At least one layer of the multi-layer core is a high specific gravity layer.

An object of the present invention is to provide a golf ball having a decreased spin rate on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein the spherical core is formed from a rubber composition containing (a) a base rubber, (b) a compound represented by the formula (1) as a co-crosslinking agent, and (c) a crosslinking initiator,

(R.sup.1COO)M(OCOR.sup.2)m(1) in the formula (1), M represents a metal atom, m represents 1 or 2, R.sup.1 and R.sup.2 are different from each other, represent an alkenyl group having 2 to 30 carbon atoms or an alkynyl group having 2 to 30 carbon atoms and have a carbon-carbon double bond or a carbon-carbon triple bond at an -position carbon atom bonding to the carbonyl group, and when m is 2, two of R.sup.2 may be identical to or different from each other.

An object of the present invention is to provide a golf ball having a decreased spin rate on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein the spherical core is formed from a rubber composition containing (a) a base rubber, (b) two or more ,-unsaturated carboxylic acids having 3 to 14 carbon atoms and having no substituent group at a carbon atom bonding to the carboxy group, and/or a metal salt thereof, and (c) a crosslinking initiator.

In a multi-piece solid golf ball having a core, a cover and an intermediate layer therebetween, the core, an intermediate layer-encased sphere and the ball have surface hardnesses which satisfy a specific relationship, and the intermediate layer and the cover have thicknesses which satisfy a specific relationship. Also, the core has a hardness profile in which the hardnesses at the core surface, core center, a position 5 mm from the core center, and a position midway between the surface and center of the core satisfy specific relationships. This golf ball, when used by mid- and high-level amateurs, enables the golfer to maintain an adequate distance on shots with a driver and achieve a good distance on iron shots, has a good spin performance on approach shots and has a good feel on impact. In addition, the ball has an excellent scuff resistance when struck with a grooved wedge.

A golf ball for amateur golfers exhibits excellent flight characteristics when hit by the average golfer and also has a good feel at impact that is both soft and solid. The golf ball includes a core, an intermediate layer and a cover, and has coefficient of restitution and compressive deformation relationships that satisfy specific conditions.

In a golf ball having a core, an intermediate layer and a cover, the intermediate layer-encased sphere has a higher surface hardness than the ball. The core hardness profile in the ball is designed such that the core surface has a Shore C hardness value which is at least 27 higher than the Shore C hardness value at the core center, and the surface areas A to F calculated from hardness differences between positions located at specific distances in the core and differences between the specific distances satisfy a specific formula. This golf ball has an excellent flight performance when struck by skilled amateur golfers and professionals, and also has a good controllability on shots with an iron.