Abstract: A chuck that includes jaws, a first housing, which has a jaw cavity into which the jaws are received, a shaft and a second housing. The shaft and jaws are coupled so that relative rotation between the shaft and the first housing translates the jaws so that they converge toward or diverge from the shaft's rotational axis. The second housing includes a chuck cavity into which the first housing is received, and an opening that extends through the second housing and intersects the chuck cavity. The chuck is resistant to infiltration of debris and/or has an easily accessed interior that can be cleaned. In one example, the chuck includes a means for inhibiting infiltration of debris through the opening into the chuck cavity. In another example, the second housing has two portions that may be uncoupled from one another to permit access to an interior portion of the chuck.