Use of Dakekanba Wood for Baseball-bats

is a pioneer species that has not been used sufficiently in practical applications even though it is the most abundant wood source in the Hokkaido prefecture. We believe that it has potential as a valuable material for use in baseball bats. Assuming that the critical factor for baseball bats is an impact strength, we elucidated the relationships between slope of grain （(cid:9495)(cid:9523)(cid:9483)） and impact strength or impact fracture energy of dakekanba wood by conducting impact bending tests. Results revealed that the Hankinson equation could be used to calculate these relationships to impact strength because they were similar to those considered in previous studies of impact fracture energy. Cylindrical wood specimens such as bat grips were assessed in the impact bending tests, and dakekanba wood was compared with woods used for commercial bats. After impact strength were corrected based on (cid:9495)(cid:9523)(cid:9483) and density, both strength and fracture energy of dakekanba wood were found to be nearly the same as those of commercial wood species for baseball bats. Prototype bats of dakekanba wood were manufactured and experimentally used by a baseball club at Kyoto University. The prototypes were confirmed to have sufficient durability, as no bats broke during their one-week trial use. On a questionnaire survey, players responded with “good” or “normal” regarding bat feeling, flown distance, etc. after hitting with the prototypes. Our study reveals that dakekanba wood has good potential as a baseball-bat material.