For bore sizes 3-1/4" to 3" The GB Series Flex-Hone tools are designed for bore diameters from 3-1/4" thru 4-5/8" and are 13-1/2" OAL. These standard duty Flex-Hones tools are commonly used to finish and deglaze block cylinders or liners and represent a tremendous value on a cost per cylinder basis. The Flex-Hone® tool is always used in an oversized condition. Our sizes are listed by the nominal bore in which the hone is intended to be used.
