9/16" x 1/2"
NOTE: We had to make a copy of the original hub, and by the nature of the reproduction process, the front lip of the mushroom does not have as much texture as the original hub. This is an artefact of the process and is not considered a defect.
NOTE: Because of the front lip of the mushroom, your metal may stick in the die more than others. Always leave a small lip around the impression to assist when removing your metal. For best results, lightly oil the impression die to make removing your metal easier.