Taken from the USBC web site.
Markings
Any bowling ball used in USBC sanctioned
competition must be approved and identifiable as a ball
listed in the “approved bowling ball†list located on the
Specifications and Certifications page on
www.bowl.com.
Additionally, for identification purposes, each ball must
have some form of serial number (this may be engraved or
re-engraved by the bowler). Since all bowling balls manufactured
prior to the creation of the ball list (January 1991)
have been previously approved, the acceptance of these
balls is at the discretion of the tournament director and/or
league official.
Material:
1. The ball shall be constructed of solid material ie: no
liquids, and without voids in its interior.
2. Any materials added to or included in the coverstock
shall be equally distributed throughout the entire
coverstock of the ball, except for materials used in
logos and other required markings.
3. The density of any piece/component in a ball (i.e.: core,
coverstock, weight block, etc.) shall not exceed
3.80 g/mL (i.e.: no pure metals or high density materials).
4. Following approval of the ball, the introduction of
substances that are not comparable to the original
material used in manufacturing of a bowling ball is
prohibited. Likewise, altering a bowling ball in any
way so as to increase its weight or cause it to be off
balance outside the specifications is prohibited.
Surface:
The surface of the ball shall be free of all depressions or
grooves of specific pattern, except for holes or indentations
used for gripping the ball, identification lettering and
numbers, and incidental chipping or marking caused by
wear. Engraved pictures are not considered grooves of
specific pattern.
Edited on 3/23/2005 10:42 AM
