Mercer Abrasives 332040, 4-1/2" x 40 grit, premium zirconia, high density flap discs are the extended life wear version of the Aluminum Oxide style
Type 29
They're better suited for grinding and blending tougher materials like cast iron and stainless steel
Standard flap discs are best suited for general grinding applications and high density are perfect for grinding contours and irregular shapes
High density discs contain 40% more abrasive material than standard discs
Features include fiberglass backing, heavy X-weight cloth, resin on resin bond
Fast and cool cutting with no need to switch from grinding wheel to resin fibre disc
Grind, blend, and finish in one easy step
Type 29 shape is for maximum aggression
Use for all-purpose sanding and grinding of ferrous and non-ferrous metals
Best for welds and blending, rust removal, and light deburring
