Osborn 0003213700 Nylon Cup Brush 4 in 80 Grit 6000 Rpm

Product Description

The OSBORN 0003213700 is a straight cup brush designed for surface preparation, cleaning, and finishing work on metal, composite, and masonry surfaces. Filled with nylon bristles impregnated with silicon carbide abrasive at 80 grit, it delivers medium-grade cutting action without the wire fatigue or rust associated with steel-fill brushes. The 4-inch diameter cup profile concentrates abrasive contact across a defined work area, making it effective for deburring, blending, and paint or scale removal. It is rated to a maximum of 6,000 RPM and mounts via a standard 5/8-11 threaded arbor. Metalworkers, fabricators, and maintenance technicians use this brush with angle grinders in production and field service settings.

This cup brush suits applications where a consistent medium-grit finish is required on curved or flat workpieces. The nylon-silicon carbide fill is particularly well-matched for work on aluminum, stainless, plastics, and other materials where steel wire would contaminate or gouge the substrate. The 1.5-inch trim length provides moderate flexibility in the bristle stroke, allowing the brush to conform to irregular surfaces while maintaining abrasive contact. It is sold individually and is appropriate for both shop and on-site use by metal fabricators, industrial maintenance crews, and skilled tradespeople.

Key Features

• Nylon fill impregnated with 80-grit silicon carbide abrasive for medium-grade surface action
• 4-inch cup diameter concentrates cutting contact on the work area
• Straight brush profile for use with standard right-angle grinders
• 5/8-11 threaded arbor hole fits common angle grinder spindles
• Rated to 6,000 RPM maximum operating speed
• 1.5-inch trim length allows bristle flex and surface conformance

Compatibility

Designed for use with angle grinders and bench tools equipped with a 5/8-11 threaded spindle. Confirm that the tool speed rating does not exceed 6,000 RPM before mounting.

Installation Notes

Installation and use of cup brushes should be performed by qualified personnel familiar with abrasive tool safety per ANSI B7 standards. Power down and isolate the grinder before mounting or removing the brush. Confirm spindle thread compatibility and ensure the brush is fully seated and torqued before operation. Always inspect the brush for damage before each use and operate within the rated maximum RPM; exceeding the speed rating is a serious safety hazard.