Yellow Cloth Cartridge Rolls: Sizing, Mounting & Mandrel Guide

A cartridge roll that isn't mounted right won't cut or color right, no matter how good the cloth is. Here's how Pro-Graad's yellow treated cloth rolls are built, how they mount, and which mandrel length actually fits the work in front of you.

Cartridge rolls solve a problem flat buffing wheels can't touch: the inside of a bore, the back of a casting, a recess a flat wheel will never reach square-on. A yellow cloth cartridge roll mounted on a mandrel turns a die grinder or rotary tool into a precision polishing instrument for exactly those spots.

01What the Yellow Cloth Roll Actually Is

Pro-Graad Yellow Cloth Cartridge Rolls are built by tightly winding yellow treated polishing cloth around a cylindrical core, layer over layer, into a solid roll. That construction is what gives them a self-renewing action — as the outer wraps wear down in use, the roll keeps presenting fresh treated cloth underneath instead of glazing over and going dead.

The cloth itself is the same material used in Pro-Graad's yellow airway buffing and polishing wheels, so the cutting and coloring characteristics carry over directly. If you already know how the yellow wheel performs on a given metal, the cartridge roll will behave the same way — just in a shape built for small-diameter, recessed, and hard-to-reach work.

02Where This Roll Earns Its Keep

The straight cylinder shape is the whole point. It lets the roll work inside diameters, ports, counterbores, and tight interior corners that a flat wheel physically cannot reach square-on. That makes it a fit for both stages of a buffing job:

• Cut compositions — knocking down tool marks, light burrs, and casting texture inside a bore or recess.
• Coloring compositions — bringing that same interior surface to a bright, reflective finish once the cutting stage is done.

Use liquid or bar buffing compound matched to the stage and the metal — compound isn't included with the rolls, and running one dry shortens its life fast.

03Mounting: Glued End Onto the Mandrel

Every roll has one hard end and one soft end. The hard end is the glued end, and it's the end that threads onto the mandrel.

04Choosing a Mandrel Length

Every Pro-Graad yellow cartridge roll kit ships with a 3-1/2" (3.5") standard mandrel included — enough reach for most surface and shallow-bore work straight out of the pack. When the job goes deeper than that, longer mandrels are sold separately so you're not stuck buying a whole new kit just for reach.

Running a rotary tool instead of a die grinder — a Dremel-style tool with a 1/8" collet — use the CR-5 mandrel, sized specifically for that 1/8" shank rather than the 1/4" shank used across the CR-9 lineup. It's sold separately and isn't interchangeable with the CR-9 series.

05Roll Sizes & Pack Options

All diameters below use the same 1-1/2" length and 1/8" pilot hole, so the only real decision is diameter and pack size for how much cutting/coloring life you need on hand.

Not sure which diameter fits your bore or recess? Go smaller rather than larger — a roll that's slightly undersized still reaches the work; one that's too wide won't seat into the opening at all.