Louisville Slugger PowerizedPowerized is a term used and stamped onto Louisville Slugger Baseball bats, and patented by the Hillerich & Bradsby Co. in 1931. The Powerized" process is to harden the surface of the bat much like the bone rubbed finish of the 1920's. They introduced the "Powerized and Bone Rubbed" logo for the 1932 season and in 1933 and 1934 you will see it stamped "Powerized and Oil Tempered" which usually is a very light heat foil type print. Beginning in 1935 until present, they go with just "Powerized"