The shank of the mandrel must match the size of the power tool collet or drill chuck, and the pilot diameter must be compatible with the size of the cartridge roll.
3M 45120, Cartridge RoII Mandrel, 3/32 in x 3/4 in x 1/4 in, 7010328349
$4.11
Factory Stock, 7-10 Day Leadtime
3M Cartridge Roll Mandrel is a tool attachment that holds an abrasive cartridge roll (sold separately). Together, the mandrel and cartridge roll enable the user to grind or finish hard-to-reach areas of a workpiece, such as angles and curves. The mandrel attaches to a rotary tool such as a die grinder or drill, and comes in different sizes to fit a variety of cartridge roll sizes.

3M 22397, Roloc Disc 361F, 60 YF-weight, TR, 1-1/2 in x NH, 7000045097
3M 77558, Cubitron II Hookit Cloth Disc 947A, 77558, 40+ to 120+, 6 in x NH, Die 600Z, 7100232737
3M 22404, Roloc Disc 361F, 80 YF-weight, TR, 3 in, Die R300V, 7000045100
3M 45714, Cubitron II Hookit Cloth Disc 947A, 120+ X-weight, 3 in x NH, D/F 3HL, Die 300BE, 7100113113 
