Norton Surface Grinding Segment, Type 31, Series: 86A, 5 in Width, 6 in Height, 1-1/2 in Thickness, 30 Grit, Aluminum Oxide Abrasive, F Hardness Grade, Vitrified Bond, ME20579 Blueprint Number, Applicable Materials: 300/400 Series Stainless, Aluminum, Cast Iron, Ductile Iron, Gray Iron, Hard Carbon Steel, Soft Carbon Steel, Tile and Tool Steel, For Chuck Type: Hanchett, Mattison, Norton, Sterling, Abrasive Associates, Cortland and Cortland Bonus, Porous Porosity