The 3M Cubitron II Roloc Fibre Disc 786C is a 3-inch quick-change grinding disc designed for use on angle grinders. The Roloc twist-lock system attaches and releases in seconds without tools. Cubitron II precision-shaped grain (PSG) slices through paint, welds, and metal while self-fracturing during use to maintain consistent sharpness. The stiff fiber backing and strong resin bond resist tearing under aggressive grinding loads. Sold in 15-disc packs at 36+ extra-coarse grit. Part number 33389.
What is the Roloc attachment system and is it compatible with all angle grinders?
Roloc is 3M's proprietary quick-change twist-lock system. The disc mounts to a Roloc mandrel (sold separately) that chucks into any standard 1/4-inch hex bit holder or angle grinder quick-change adapter. You twist the disc onto the mandrel and it locks securely; twist and pull to remove.
At 36 grit, what jobs is the 786C designed for?
At 36+ extra-coarse grit, the 786C is intended for heavy stock removal, weld grinding, rust and paint stripping, and blending welds on metal. It is too aggressive for finish sanding and should be followed by finer grits for surface preparation.
How does the fibre backing differ from a film or paper backing?
Fibre backing is rigid and strong, designed to withstand the high pressure and heat generated during angle grinder grinding operations. It provides the stiffness needed for aggressive material removal, unlike the flexible film backings used on orbital sanding discs.
Does Cubitron II outperform standard ceramic or aluminum oxide fibre discs?
Yes. The precision-shaped grain in Cubitron II fractures to maintain sharp cutting edges throughout the disc's life. This results in faster cut rates and longer disc life compared to conventional aluminium oxide or standard ceramic fibre discs, reducing disc changes on heavy grinding jobs.
# 3M™ Cubitron™ II Roloc™ Fibre Disc 786C, 3 in, 36+ **Model:** `786C` **Brand:** 3M **Category:** Sanding Disc > The 3M Cubitron II Roloc Fibre Disc 786C is a 3-inch quick-change grinding disc designed for use on angle grinders. The Roloc twist-lock system attaches and releases in seconds without tools. Cubitron II precision-shaped grain (PSG) slices through paint, welds, and metal while self-fracturing during use to maintain consistent sharpness. The stiff fiber backing and strong resin bond resist tearing under aggressive grinding loads. Sold in 15-disc packs at 36+ extra-coarse grit. Part number 33389. ## Specifications | Attribute | Value | |---|---| | Product Type | Sanding Disc | | Diameter In | 3 | | Attachment | Roloc (quick-change twist-lock) | | Abrasive Type | Cubitron II (precision-shaped grain ceramic) | | Available Grits | 36+ | | Backing | Fiber | | Dust Holes | No | | Barcode (UPC) | | Source: https://www.jaspecs.com/3m/sanding-disc/786c-3m-cubitron-ii-roloc-fibre-disc-3in/