Coolest cut; significantly faster cut rates. Lowest total grinding costs. Greater durability and longest life on tough applications and stainless steel. Edge-fray resistance; excellent grain and body retention; consistent grinding throughout discs life. Cooler cutting; improved part finish and integrity. Heaviest fiber backing. Polyester Y-weight backing. 3-Ply laminate discs (yellow backing) is more aggressive; ideal when durability and long life are required.