The designation 40 was a secondary line of retail store model bats of the Hillerich & Bradsby co. that started production of this model around 1916. Jimmy Foxx signed a contract with the Hillerich & Bradsby Co on 6-11-1926. If the bat is stamped "powerized" the bat was made after 1931. The 40 model bats would have the player endorsed initials following as 40 J.F. (40 Jimmy Foxx endorse bat) In general a Jimmy Foxx Hillerich & Bradsby 40 model bat is worth about $150.-$200. in excellent-near/mint condition.