Shop our USA/ASA Slowpitch Bats for Men, Women and Youth. Free Shipping US48! Make sure to get the Bat Break in Service. Financing in Cart and Checkout. 2 Plans to choose from to Play Now & Pay Later. USA/ASA bats weights to choose from are 24 to 30 oz. The length no longer then 34 Inches long. The Barrel has to be 2 1/4 inch in Diameter. USA/ASA Bats vary in weights from 24 ounces to a maximum of 30 ounces. When choosing what weight your bat should be, go by your past experiences and the unwritten law on it is that it is always better to error on picking a bat on the lighter side versus the heavier side.