3M 6200J精密研磨塊 3M黃色鉆石精密手托 For hard to grind material, stone, glass, ceramic, metal, carbide, coites. Metal plated bond securely anchors micron graded diamonds to backing. For wet or dry applications. Durability improves when used with water or oil lubricants. 3M 6200J精密研磨塊 3M黃色鉆石精密手托