Norton 66261121289 Flap Disc 40 Grit 4.5 in Type 29

Product Description

The NORTON 66261121289 is a Type 29 zirconia alumina flap disc designed for aggressive material removal on metal surfaces. Measuring 4.5 inches in diameter with a 5/8-11 threaded arbor hole, it mounts directly to standard angle grinders without additional hardware. The coarse 40-grit abrasive cloth is layered in an overlapping flap pattern over a fiberglass backing, which resists flex fatigue and maintains disc geometry under load. Rated at 13,000 RPM, it is suited for high-speed grinding and blending passes. Fabricators, welders, and metal finishing technicians are the primary users of this disc.

This flap disc is intended for use on steels, stainless steel, and titanium. The Type 29 conical angle — as opposed to a flat Type 27 profile — increases surface contact when working at a low grinding angle, making it effective for stock removal on flat and contoured workpieces. It is commonly used in fabrication shops, structural steel work, and maintenance grinding where fast material removal at 40 grit is required before moving to finer finishing steps. The fiberglass backing withstands the lateral forces typical in angle grinder applications.

Key Features

• Type 29 conical profile for improved contact angle on flat and curved surfaces
• 40-grit zirconia alumina abrasive for coarse, fast stock removal
• 5/8-11 threaded arbor hole fits standard angle grinder spindles directly
• Fiberglass backing resists flex fatigue and maintains shape under load
• 13,000 RPM maximum speed rating for use with 4.5-inch angle grinders
• Rated for steels, stainless steel, and titanium applications

Compatibility

Designed for use on steels, stainless steel, and titanium. Fits angle grinders equipped with a 5/8-11 threaded spindle and rated for 4.5-inch accessories at or below 13,000 RPM.

Installation Notes

Installation is performed by threading the disc directly onto a 5/8-11 angle grinder spindle — no separate arbor or flange adapter is required for this attachment type. Verify the grinder's no-load RPM rating does not exceed the 13,000 RPM maximum marked on the disc before mounting. Disconnect the grinder from power before mounting or removing the disc. Always use the grinder guard and appropriate PPE, including face protection, when operating abrasive flap discs.