Norton 66623399142 Flap Disc 4-1/2 in 60 Grit Type 27

Product Description

The NORTON 66623399142 is a Type 27 zirconia alumina flap disc designed for aggressive material removal on metal, weld seams, and fabricated surfaces. It features a fiberglass backing plate that provides structural rigidity under load, and it is rated to 13,300 RPM for use with standard 4-1/2 inch angle grinders. At 60 grit, this disc falls in the coarse grade range, making it well-suited for stock removal, weld blending, and surface prep prior to finishing. The arbor attachment mounts directly to a 7/8 inch arbor, fitting the most common grinder spindles used in fabrication and field work. This is an individually packaged disc sold with a minimum order quantity of 10 units.

This flap disc is used in metal fabrication shops, structural steel work, pipeline work, and general industrial grinding applications. The Type 27 flat profile keeps the grinding surface parallel to the workpiece, which is preferred for flat and contoured surface work where a low grinding angle is needed. It is a practical choice for ironworkers, welders, pipefitters, and metal fabricators who need consistent cut rate and disc longevity on ferrous and non-ferrous materials. The R884P series designation identifies it within the NORTON line of zirconia abrasive products.

Key Features

• Type 27 flat profile for low-angle grinding on flat and contoured workpieces
• Zirconia alumina abrasive grain delivers aggressive cut rate and extended disc life compared to aluminum oxide
• 60 grit coarse grade for weld blending, stock removal, and surface preparation
• Fiberglass backing provides rigidity and durability under sustained grinding pressure
• Rated to 13,300 RPM for compatibility with standard 4-1/2 inch angle grinders
• 7/8 inch arbor hole fits the most widely used grinder spindle sizes

Compatibility

Designed for use with 4-1/2 inch angle grinders equipped with a 7/8 inch arbor spindle. Verify your grinder's no-load RPM does not exceed 13,300 RPM before mounting this disc.

Installation Notes

Installation should be performed by qualified personnel familiar with angle grinder safety practices. Power down and disconnect the grinder from its power source before mounting or removing any disc. Inspect the disc for cracks or damage before each use and never operate above the rated maximum RPM. Always use the appropriate guard for Type 27 discs as required by ANSI B11 and applicable OSHA standards.