ARLINGTON, Texas – The United States Bowling Congress has revoked approval of
Purple Hammer bowling balls manufactured in 2016 and 2017. These model years are
removed from the list of balls approved for USBC competition effective March 21, 2022.
These model years of the Purple Hammer may no longer be used in any USBC certified
competition including all USBC leagues and tournaments.
Purple Hammer bowling balls manufactured during 2016 or 2017 are identified by serial
numbers that start with either a “6” or “7”.
USBC investigated allegations that a portion of the Purple Hammer bowling balls
manufactured at the Ebonite International plant in 2016 and 2017 were produced below
USBC’s minimum hardness specification at that time of 72D. The Hammer brand was
purchased by Brunswick Bowling Products in 2019, and the Ebonite plant subsequently
After a former Ebonite employee made public comments on this matter, USBC
conducted an investigation. USBC interviewed more than a dozen individuals, including
former Ebonite employees, in an attempt to validate the claim. Brunswick fully
cooperated with the investigation. USBC’s announced initial findings on March 7, 2022
that included a national tournament rule prohibiting use of the 2016 and 2017 Purple
Following that announcement, additional information was provided to USBC causing the
investigation to be reopened. Four additional interviews were conducted.
USBC has the authority to revoke approval of a bowling ball if it determines production
balls do not comply with current specifications outlined in the USBC Equipment
Specifications and Certifications Manual. Based upon all the information gathered in the
investigation, USBC has now made this determination about the 2016 and 2017 Purple
During USBC’s investigation, former Ebonite employees, including ones with first-hand
knowledge, provided detailed statements to USBC outlining how processes in 2016 and
2017 led to some Purple Hammers being produced and sent to the field below 72D.
Multiple former Ebonite employees confirm that a production change took place in 2017
to raise the hardness of Purple Hammers produced in 2018 and 2019.
USBC has shared its determination with Brunswick and has Brunswick’s support.
Brunswick will continue to offer owners of 2016 or 2017 Purple Hammers the option to
exchange their balls for a new Purple Hammer or a product of their choice. This can be
done on-site at the 2022 USBC Open Championships or USBC Women’s
Championships, by claiming a replacement ball at http://www.hammerbowling.com/Purple, or
by contacting Brunswick at email@example.com or 800-937-
Unapproved bowling balls may not be used in USBC certified competition. Bowlers who
used 2016 and 2017 Purple Hammers in competition before March 21, 2022 with no prior
knowledge of their balls being out of specification would not be subject to forfeiture
under USBC rules.
United States Bowling Congress
The United States Bowling Congress serves as the national governing body of bowling as
recognized by the United States Olympic & Paralympic Committee (USOPC). USBC
conducts championship events nationwide including the largest participation sporting
events in the world – the USBC Open and Women’s Championships – and professional
events such as the USBC Masters and USBC Queens.
Founded in 1895, today USBC and its 1,519 state and local associations proudly serve
more than a million members. USBC is headquartered in Arlington, Texas, working
toward a future for the sport. The online home for USBC is BOWL.com.