Norton 66623399136 Flap Disc 36 Grit Type 27 4.5 in

Product Description

The NORTON 66623399136 is a Type 27 zirconia alumina flap disc engineered for aggressive material removal on angle grinders. It carries a 36 grit rating, placing it in the very coarse grade category, which is suited for heavy stock removal, weld leveling, and surface conditioning on steel and other metals. The disc spins at a rated maximum of 13,300 RPM and mounts via a 5/8-11 arbor hole. The cloth backing provides durability under load, and the trimmable design allows technicians to expose fresh abrasive as the disc wears, extending usable service life.

This flap disc is intended for use with standard 4.5-inch angle grinders commonly found in fabrication shops, construction sites, and industrial maintenance environments. It is appropriate for tasks such as grinding weld beads, deburring cut edges, and blending surfaces on structural steel, plate stock, and similar ferrous materials. The Type 27 flat profile keeps the disc flush to the workpiece, making it the preferred configuration for flat surface work rather than edge grinding. Installation is performed by licensed tradespeople and skilled operators working within applicable safety standards for portable grinding equipment.

Key Features

• 36 grit zirconia alumina abrasive for aggressive, very coarse stock removal
• Type 27 flat profile optimized for flat surface grinding applications
• Rated to 13,300 RPM maximum operating speed
• 5/8-11 arbor attachment for compatibility with standard angle grinders
• Cloth backing delivers durability and flexibility under sustained grinding pressure
• Trimmable construction allows controlled exposure of fresh abrasive as the disc wears

Compatibility

Designed for use with angle grinders accepting a 5/8-11 arbor and accommodating a 4.5-inch disc diameter. Verify that the grinder guard and spindle speed rating meet or exceed the 13,300 RPM maximum disc rating before mounting.

Installation Notes

Always power down and disconnect the grinder from its power source before mounting or removing a flap disc. Confirm the spindle speed rating of the grinder does not exceed the maximum RPM marked on the disc. Wear appropriate PPE including a face shield, gloves, and hearing protection during operation. Follow ANSI B7.1 safety standards for the use, care, and protection of abrasive wheels.