Sherline's 3072 1/4" chuck includes a #1 Morse arbor so that it can be mounted in the headstock of the lathe or mill. P/N 3072 has the same size capacity as the P/N 1072 chuck above, which is 1/16" to 1/4". P/N 3072 is usually purchased when it will be used only for drilling in a mill where the #0 Morse arbor is not required. Included is a drawbolt (not shown) to draw the #1 Morse arbor into the taper of the headstock spindle.