Hex shank drill bit set classic HSS construction with titanium coating for capability and durability.The cutting edge is hardened and honed for sharpness, chatter-free design with staggered cutting teeth ensure the precise countersinking and hole smooth clean. Carbide metric drill bits 2 flutes form helps clear chips and debris away from the bit, decreasing friction and heat for a faster, cooler drilling process. 1/4 inch hex shank fits into all power tools more easily and securely, specially for locking into quick change chuck. Great drill bits set for metal/wood/plastic countersink. Suitable for Home DIY, and General Building/Engineering Use. Metric drill bit set hex shank 1.5-6.5mm Contains 1PC×1.5MM, 1PC×2.0MM, 1PC×2.5MM, 1PC×3.0MM, 1PC×3.2MM, 1PC×3.5MM, 1PC×4.0MM, 1PC×4.5MM, 1PC×4.8MM, 1PC×5.0MM, 1PC×5.5MM, 1PC×6.0MM, and 1PC×6.5MM.