Ouba Semi Automatic Hand Drill Mini Micro Twist Drill Bits Wood Model Manual Assortment 10pcs per Set Unique bit retention system keeps bits in place and makes different sizes easy to identify Drill bits have a titanium coating that provides longer life when drilling in non-ferrous metals. These bits are also suitable for drilling in wood and plastic and are ideal for commercial and residential applications. 135-degree split point starts on contact, no walking or skating, reduces feed pressure for easier penetration without work hardening. Each drill bit has a heavy-duty spiral flute design that produces fast chip ejection, lifetime warranty, 30 day no-risk trial