These bats have great durability for a non-plastic bat. The drier you keep them the longer they will last. Don't soak them. Soften up any old clay left on them with a damp sponge and you will be able to easily scrape them clean on your potter's wheel. We like to keep some on hand for each of the different clay bodies we use to prevent cross-contamination of clays with different firing temperatures. The standard bat is 11 3/4" in diameter cut from 1/4" premium Duron Masonite for longevity, water resistance and dimensional stability. They have die cut holes for bat pins. The die cutting process ensures exact hole dimensions on every bat. Holes fit standard wheelheads with two pins located 10 inches on center. Please confirm these dimensions on your wheel before ordering. Adjustments can be made in the bats using a rat tail file to compensate for normal, small variations in wheelhead dimensions.