Forney Industries Inc 71991 Flap Disc 4 in 36G Type 29

Product Description

The FORNEY INDUSTRIES INC 71991 is a 4-inch, Type 29 depressed-center flap disc designed for use with right angle grinders. Built with blue zirconia abrasive cloth, it is engineered for aggressive stock removal and extended service life. Multiple overlapping zirconia cloth flaps continuously expose fresh, sharp grinding points as the disc wears, maintaining cut rate throughout the disc's life. The reinforced fiberglass backing plate provides structural support under load, and each disc is balance-tested at the factory to minimize vibration during grinding and finishing operations. The 5/8-inch arbor fits standard right angle grinder spindles.

This flap disc is suited for metal fabrication, weld blending, deburring, and surface preparation tasks where both material removal and finish quality matter. The Type 29 depressed-center geometry increases the contact angle, making it effective on flat surfaces, contoured workpieces, and edge work. At 36 grit, it is positioned for rough grinding and rapid stock removal while retaining enough flexibility for transition work before finer finishing passes. This disc is packaged in a quantity of 10 units per package, making it practical for shop stocking.

Key Features

• 4-inch diameter with 5/8-inch arbor fits standard right angle grinders
• 36 grit blue zirconia abrasive for aggressive cut rate on metal
• Type 29 depressed-center profile increases surface contact angle
• Multiple layered flaps continuously expose new sharp abrasive points
• Reinforced fiberglass backing plate supports the disc under grinding loads
• Each disc balance-tested at the factory for vibration-free operation

Compatibility

Designed for use with right angle grinders accepting a 5/8-inch arbor. Suitable for grinding and finishing applications on metal surfaces in fabrication, maintenance, and repair environments.

Installation Notes

Install and operate this flap disc in accordance with ANSI B7.1 safety requirements for abrasive wheels. Always power down and disconnect the grinder before mounting or removing a disc. Verify that the grinder's rated RPM meets or exceeds the disc's rated speed before operation. Wear appropriate PPE including face shield, gloves, and hearing protection during use.