100mm P120 SiC Cup Brush

A 100mm P120 SiC cup brush is a power-brush consumable for surface finishing on rotary tools, most commonly a 100mm or 125mm angle grinder. The cup-shaped head has a 100mm diameter working face and a 35mm deep trim of abrasive nylon filaments loaded with silicon carbide. The base is machined from 6061 aluminum alloy with a standard M14 x 2.0 female thread, so the brush installs directly onto compatible spindles.

In operation, the tool spins the cup face and the operator guides it over the workpiece. The brush is designed for flat and slightly contoured surfaces: the face works wide areas, and the outer rim handles edges, weld zones, and shallow transitions. Light to moderate pressure keeps the filaments cutting instead of bending flat.

P120 is a medium-fine grit. That makes this a finishing and conditioning tool, not a heavy stock removal or aggressive descaling tool. Remove heavy rust, mill scale, weld spatter, or thick coating first with a wire brush, grinding disc, or coarse abrasive. The cup brush then refines the surface to a uniform line before the next process.

The table below lists the standard configuration. Diameter, trim depth, grit, thread, and bristle density can be adjusted for project-specific finishing work.

• Deburring and edge blending on laser-cut, punched, or CNC-machined parts where sharp edges need softening without changing dimensions.
• Removing light oxidation, weld discoloration, and heat tint from stainless steel and aluminum before passivation, coating, or assembly.
• Satin finishing and scratch blending on flat panels, architectural profiles, handrails, and enclosures.
• Surface preparation before paint, powder coat, bonding, or plating by creating a controlled anchor pattern without deep gouges.
• Cleaning mold release, light flash, and surface haze from composite, fiberglass, and hard plastic parts.
• Blending weld seams on sheet metal assemblies where a visible grain direction is acceptable.

The 100mm P120 SiC cup brush is a specific configuration. The remaining decisions are whether this diameter and grit fit your surface, and whether your tool can run it safely.

Match the thread and guard first

Confirm your spindle is M14 x 2.0. If it is a different size, request an alternate thread or adapter hub. Check that the grinder guard clears a 100mm accessory and that the tool no-load speed is at or below 9,000 RPM. If the grinder has variable speed, set it within the 4,500–8,000 RPM working range.

Choose the grit and filament aggressiveness for the finish requirement

P120 handles fine burrs, light oxide, heat tint, and satin blending. For heavier scale or deeper scratches, start with P80/P60 in the same cup or use a wire cup brush first. For a smoother, more refined surface, follow with P180/P240 or a non-woven conditioning brush. To increase cut without changing grit, specify a shorter trim, larger filament diameter, or higher bristle density. To improve conformance around contours, use a longer trim or smaller filament diameter.

Consider the workpiece material

Silicon carbide is sharp and friable, so it works well on stainless steel, aluminum, titanium, hard alloys, glass-reinforced composites, and hard plastics. On very soft metals such as copper, brass, or pure aluminum, P120 may cut faster than intended and leave a visible grain. Use lighter pressure, lower speed, a finer grit, or test on scrap first. For wood, the cup face can load or generate heat at high speed; a flap brush or disc is often a better fit.

Use the right operating practice

Keep the brush moving and use light to moderate pressure. Let the abrasive do the work. Excessive pressure bends the filaments flat, increases heat, and shortens life. On large flat areas, overlap passes by about half the brush face to avoid visible lane lines.

The 100mm P120 SiC cup brush is built around standard angle grinder mounting, but the cup geometry, abrasive grade, and connection can be adjusted for a production finishing line.

• Brush diameter and working face depth: 80, 100, 115, or 125mm diameters; shorter or longer trim to change stiffness and aggressiveness.
• Abrasive grade and material: P60 through P320 in silicon carbide, aluminum oxide, or ceramic-loaded nylon depending on the surface and finish requirement.
• Filament construction: filament diameter, straight or crimped configuration, density, and distribution pattern to tune cut, loading, and surface grain.
• Cup profile: flat face, flared rim, conical, or special edge profile for access into a specific part geometry.
• Hub and thread: M14 standard; M10, 5/8-11, or custom arbor/adapter; aluminum, steel, or fiberglass-reinforced nylon base.
• Color and marking: custom bristle color, laser marking on the hub, product code, or private label packaging.
• Packaging: bulk, individual sleeve, blister, or project-specific kitting.

To define a custom configuration, send the tool spindle thread, no-load RPM, workpiece material, current surface condition, target finish or Ra value, and a photo or drawing of the part geometry. For industrial programs, we can also support material data, first article samples, inspection criteria, and project documentation.