Osborn 0003356100 Knotted Cup Brush 2-3/4 in Steel

Product Description

The OSBORN 0003356100 is a knotted steel wire cup brush designed for aggressive surface preparation on metal, welds, and castings. Measuring 2.75 inches in diameter with a 0.02-inch wire diameter and a 7/8-inch trim length, this single-row cup brush delivers concentrated abrasive action for removing rust, scale, weld spatter, and mill scale. It is rated to 14,000 RPM and features a 5/8-11 threaded arbor for direct mounting to standard angle grinders. Knotted wire construction provides greater cutting aggression than crimped wire, making it a go-to choice for fabricators, welders, pipefitters, and maintenance technicians working on heavy-duty surface conditioning tasks.

This cup brush is suited for use in industrial, commercial, and trade environments where fast, efficient surface cleaning or prep is required before coating, welding, or inspection. Common applications include weld bead cleanup, paint and coating removal, rust stripping on structural steel, and general deburring. The 5/8-11 arbor thread fits most standard right-angle grinders used in fabrication shops, field pipework, and maintenance operations. Single-row knotted construction concentrates wire contact for maximum material removal rate on ferrous surfaces.

Key Features

• Knotted wire construction for aggressive cutting action on rust, scale, and weld spatter
• 2.75-inch brush diameter with 0.02-inch wire diameter for focused abrasive contact
• 14,000 RPM maximum speed rating for use with standard angle grinders
• 5/8-11 threaded arbor for direct, secure mounting without adapters
• 7/8-inch trim length provides consistent wire projection and brush life
• Single-row design concentrates wire density for efficient surface prep

Compatibility

Designed for use with angle grinders and die grinders fitted with a 5/8-11 threaded spindle, which is the standard arbor size on most 4-inch to 5-inch right-angle grinders used in fabrication and trades work.

Installation Notes

Installation and operation should be performed by qualified trades personnel familiar with abrasive power tool safety. Always disconnect or de-energize the grinder before mounting or removing the brush. Thread the 5/8-11 arbor fully onto the grinder spindle and confirm it is secure before applying power. Wear appropriate PPE including face shield, gloves, and hearing protection. Do not exceed the 14,000 RPM maximum rated speed. Follow ANSI B7.1 and applicable workplace safety standards for abrasive wheel and wire brush use.