Norton 66623341107 Flap Disc 4-1/2 in 36 Grit Type 29

Product Description

The NORTON 66623341107 is a Type 29 zirconia alumina flap disc built for aggressive material removal on steel and similar metals. It measures 4-1/2 inches in diameter with a 7/8-inch arbor hole and runs at a maximum of 13,300 RPM. The disc carries a 36-grit coarse abrasive, making it well-suited for heavy stock removal, weld blending, and surface conditioning where fast cut rate matters. A fiberglass backing plate supports the flap arrangement and helps maintain disc shape under lateral grinding pressure. Part of the NORTON R860 series, this disc is intended for use with standard angle grinders in fabrication and maintenance applications.

This flap disc is used in metalworking environments where rapid removal of weld spatter, mill scale, or surface rust is required. The Type 29 conical design positions the abrasive flaps at an angle, which increases surface contact and improves cut rate compared to a flat Type 27 profile. Typical applications include structural steel fabrication, pipe weld prep, and general metal finishing in both shop and field settings. The blue zirconia alumina grain is self-sharpening, which helps maintain a consistent cut rate over the disc life.

Key Features

• Type 29 conical profile increases contact area for faster stock removal
• 36-grit zirconia alumina grain — self-sharpening, suited for coarse metal work
• Fiberglass backing plate provides structural support under side-load grinding
• Rated to 13,300 RPM for use with standard 4-1/2-inch angle grinders
• 7/8-inch arbor hole fits most common angle grinder spindles
• Part of the R860 series, designed for steel and ferrous metal applications

Compatibility

Designed for use with 4-1/2-inch angle grinders equipped with a 7/8-inch arbor. Intended for use on steels and ferrous metals per manufacturer specification.

Installation Notes

Installation and disc changes should be performed by a qualified operator following the grinder manufacturer's instructions and ANSI B7.1 safety standards. Always confirm the grinder's free-speed RPM does not exceed the disc's 13,300 RPM rating before mounting. Inspect the disc for cracks or damage before each use and discard any disc that shows signs of delamination or flap separation. Wear appropriate PPE including face shield and gloves when operating angle grinders.