Norton 63642503511 Flap Disc 40 Grit 4.5 in Type 27

Product Description

The NORTON 63642503511 is a Type 27 zirconia alumina flap disc engineered for aggressive material removal on metal surfaces. The disc measures 4.5 inches in diameter with a 5/8-11 threaded arbor hole for direct mounting to standard angle grinders. At 40 grit coarse grade, it cuts quickly through welds, scale, and surface imperfections. The fiberglass backing plate provides rigidity and support throughout the disc life. Rated to 13,000 RPM, it suits high-speed grinder operation in fabrication shops, field welding, and structural steel work. The R822 series blue disc is a go-to for metalworkers and fabricators handling tough grinding tasks.

This flap disc is suited for use on steels, stainless steel, and titanium. It fits residential and commercial fabrication environments where controlled, flat grinding is required. The Type 27 flat profile is the standard choice when working on flat surfaces or inside corners, and the threaded arbor attachment makes tool changes fast without additional hardware. It is commonly used by welders, ironworkers, pipefitters, and metal fabricators performing weld blending, stock removal, and surface preparation.

Key Features

• 40 grit coarse grade for rapid stock removal and weld blending
• Zirconia alumina abrasive material for long service life on ferrous and non-ferrous metals
• Type 27 flat profile designed for flat surface and inside-corner grinding
• 5/8-11 threaded arbor hole for direct mount on standard angle grinders
• Fiberglass backing with X-weight construction for rigidity under load
• 13,000 RPM maximum speed rating suitable for high-speed grinders

Compatibility

Designed for use on steels, stainless steel, and titanium. Fits any standard angle grinder with a 5/8-11 threaded spindle accepting a 4.5-inch Type 27 flap disc.

Installation Notes

Mounting and disc changes should be performed with the grinder unplugged or the battery removed. Verify the grinder spindle speed does not exceed the 13,000 RPM disc rating before use. Eye protection, gloves, and a face shield are standard PPE for grinding operations. Inspect the disc for damage before each use and discard any disc showing cracks, tears, or delamination in the flaps.