A 3.5" (90 mm) diameter part is the largest part that can be accommodated in the standard Sherline lathe. Yet, occasionally it may be necessary to work on something larger. The Sherline headstock spacer block increases the maximum working diameter of the lathe to 6" (152mm). P/N 1297 includes a 1-1/4" (32 mm) spacer block to fit under the lathe headstock. This useful accessory aligns the lathe spindle with the MK-III Bed Turret to greatly expand the lathe's capability to produce multiple parts.