Norton 66623341104 Flap Disc 36 Grit 4-1/2 Inch Type 29

Product Description

The NORTON 66623341104 is a Type 29 zirconia alumina flap disc designed for aggressive material removal on metal surfaces. Part of the R884P series, it runs at a maximum of 13,300 RPM and carries a 36-grit extra coarse designation, making it suited for heavy grinding, weld blending, and surface conditioning where fast stock removal is the priority. The disc measures 4-1/2 inches in diameter with a 5/8-11 arbor hole and is backed by a fiberglass plate that supports the conical flap arrangement characteristic of Type 29 geometry. Fabricators, pipefitters, ironworkers, and sheet metal technicians are the primary installers of this disc.

This disc is used on 4-1/2 inch angle grinders in residential, commercial, and industrial fabrication settings. The Type 29 profile presents the abrasive cloth at an angle to the workpiece, which increases contact area and grinding aggressiveness compared to a flat Type 27 disc. It is commonly applied to mild steel, stainless steel, and other ferrous metals during weld seam removal, edge chamfering, and surface preparation ahead of coating or inspection. The extra coarse 36-grit configuration prioritizes removal rate over finish quality.

Key Features

• Zirconia alumina abrasive delivers high cut rate and extended disc life on ferrous metals
• Type 29 conical geometry increases grinding contact angle for aggressive stock removal
• 36-grit extra coarse grade optimized for weld blending and heavy surface conditioning
• Fiberglass backing plate provides structural rigidity and supports high-RPM operation
• 5/8-11 arbor hole fits standard 4-1/2 inch angle grinders directly without an adapter
• 13,300 RPM maximum speed rating suits common corded and cordless angle grinders

Compatibility

Designed as a direct-mount replacement or standard-use flap disc for 4-1/2 inch angle grinders equipped with a 5/8-11 threaded spindle.

Installation Notes

Installation and disc changes must be performed by a qualified operator with the grinder fully powered down and the power source disconnected. Verify the grinder spindle speed does not exceed the 13,300 RPM maximum rating marked on the disc before mounting. Thread the disc onto the 5/8-11 spindle by hand until seated, then tighten according to the grinder manufacturer guidance — do not overtighten with tools in a way that cracks the fiberglass backing. Always inspect the disc for damage before each use and wear appropriate eye, face, and hand protection during operation in accordance with ANSI B11 and applicable shop safety codes.