452.4 CoroDrill 452 Solid Carbide Drill With External Coolant Grade CM H10F For aerospace rivet and bolt holes, you can't go wrong with this assortment of these new drills. Each carbon fibre material can be different which then varies the risk for delamination or splintering. These drills, optimized for composite- and metallic-stack materials, ensure the stringent hole tolerances are met with exceptional finish and quality. Available as standard products with 24-hour delivery as well as engineered solutions for specific application demands.