Designed for use in standard lock mortising tools, these cutters can also be used in a standard router if mounted on a separate arbor.
Note: #55251 is Down-Shear.
For 1/4" shank use arbor #47611.
For 1/2" shank use arbor #47614.
#55255 uses arbor #47616.
Please note that these are the cutters only! The below tools do not include the arbors.