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 45119, Cartridge Roll Mandrel, 1/8 in x 1 in x 1/4 in, 7000045771
$3.36
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.

Dynabrade 40320 Dynafile II Abrasive Belt Tool
3M 77559, Cubitron II Hookit Cloth Disc 784F, 77559, 36+ to 120+, 5 in x NH, Die 500X, 7100232738
3M 06467, Cut & Grind Wheel, Type 27, 7 in x 1/8 in x 5/8"-11, Quick Change, 7100218056, 20 per case
3M 33439, Cubitron II File Belt, 33439, 60+, 10 mm x 330 mm (3/8 in x 13 in), 7100033194, 10 belts per carton, 5 cartons per case
Dynabrade 95821 Dynabrade Air Lube 10W/NR, 4oz Bottle
Dynabrade 14360 Pneumatic Pipe Belt Finisher
Dynabrade 53270 7" (180 mm) Dia. Right-Angle Disc Sander
Dynabrade 14010 Dynafile Abrasive Belt Tool Versatility Kit
Dynabrade 11486 Dynabelter Accu-Grinder Abrasive Belt Tool, Heavy-Duty
Dynabrade 93533 7" Mandrel for Sanding Stars w/ Flexible Tip, 3-48 Male Thread 
