3M 7100242990 Ceramic Flap Disc 120 Grit Type 29

Product Description

The 3M 7100242990 is a ceramic abrasive flap disc designed for aggressive material removal and surface blending on metal workpieces. It features a Type 29 conical profile that increases contact angle and cutting pressure, making it well-suited for weld grinding, deburring, and stock removal on flat or contoured surfaces. The ceramic abrasive grain self-sharpens during use, extending disc life compared to aluminum oxide alternatives. A plastic backing plate provides rigidity while keeping overall disc weight low at 0.22 pounds. This disc is sized at 4.5 inches in diameter with a 5/8-11 threaded center hole for direct mount on standard right-angle grinders.

This flap disc is intended for use by metal fabricators, welders, pipefitters, and maintenance trades working on steel, stainless steel, and other hard metals. The 120-grit rating positions it for finishing and blending passes after coarser stock removal, producing a consistent surface finish. Its coated abrasive construction and Type 29 geometry make it a practical choice for both flat grinding and work on angled or beveled joints.

Key Features

• Ceramic abrasive grain for extended cut life and self-sharpening action
• Type 29 conical profile increases cutting angle for aggressive stock removal
• 120-grit coated abrasive surface for finishing and blending
• 5/8-11 threaded center hole fits standard right-angle grinders directly
• Plastic backing plate provides rigidity at low weight (0.22 pounds)
• 4.5-inch diameter suits common 4.5-inch angle grinder guard configurations

Compatibility

Designed for use with standard right-angle grinders equipped with a 5/8-11 threaded spindle, which is the common spindle standard for 4.5-inch class grinders.

Installation Notes

Installation is performed by licensed or experienced trade professionals and qualified fabricators. Before mounting, confirm the grinder's rated RPM meets or exceeds the disc's maximum rated speed and verify the spindle thread is clean and undamaged. Power down and disconnect the grinder from its power source before changing discs. Inspect the disc for cracks or damage before each use and never use a damaged disc.