Various Sizes: 115pcs drill bit sets including 29pcs fractional drill bits. M35 Cobalt Drill Bit: The M35 cobalt drill bit is a durable, sharp, and sturdy drill bit ideal for cutting stainless steel, cast iron castings, copper, aluminum, and other soft metals, as well as plastic, wood, etc. Fast and Efficient: This cobalt drill bit set is suitable for most objects, whether soft or hard. Its 135-degree point and helical design provide faster cutting, self-centering to prevent dropping, and faster chip and particle removal. M35 HSS Drill Bit Set: Short length HSS drill bit kit for hardened steel with excellent cutting performance. 115pcs drill bit sets for long-lasting use. The inserts are hardened and polished for improved sharpness and precise cutting without wobble. Easy Storage: The drill bit set includes drill bit holders with size indexes and is packaged in a compact and sturdy package for easy storage and sorting.