Norton 66623399051 Flap Disc 60 Grit Zirconia Alumina Type 29

Product Description

The NORTON 66623399051 is a Type 29 zirconia alumina flap disc designed for grinding and blending on steel surfaces. The disc measures 4 inches in diameter with a 5/8 inch arbor hole and runs at a maximum of 15,300 RPM. Type 29 geometry angles the flaps for aggressive stock removal while maintaining consistent scratch patterns across the work surface. The fiberglass backing provides rigidity under load without adding excessive weight. At 60 grit medium grade, this disc suits weld blending, surface prep, and edge work on structural and fabricated steel components. Licensed trade professionals and fabricators install these on angle grinders as part of standard surface finishing workflows.

This flap disc is suited for use on steel substrates in both fabrication shop and field service environments. The zirconia alumina abrasive grain is self-sharpening under pressure, which helps maintain cut rate over the life of the disc. The blue fiberglass backing and R860 series designation indicate this is a production-grade disc built for sustained use. Typical applications include weld seam blending, scale removal, and surface conditioning on mild and structural steels. It is sold individually with a minimum order quantity of 10 units.

Key Features

• Type 29 angled flap geometry for aggressive grinding and blending
• Zirconia alumina grain with self-sharpening characteristics under load
• 60 grit medium grade suited for weld blending and surface prep on steel
• Fiberglass backing for rigidity and durability during sustained use
• 15,300 RPM maximum speed rating for standard angle grinder compatibility
• 5/8 inch arbor hole with 4 inch disc diameter

Compatibility

Designed for use on steel material applications. Fits angle grinders accepting a 4 inch disc with a 5/8 inch arbor hole. Part of the NORTON R860 series.

Installation Notes

Install and replace flap discs with the grinder fully powered off and unplugged. Verify the grinder spindle speed does not exceed the 15,300 RPM disc rating before use. Wear appropriate PPE including eye protection and gloves when mounting or operating abrasive discs. Follow ANSI B7.1 and grinder manufacturer guidelines for proper disc mounting and guard use.