21-Piece Titanium Coated Drill Bit Set. This set is perfect for a wide variety of drilling applications, suitable for use with wood, metal, and plastic. The titanium coating increases the life of the bits by keeping them cooler while drilling, which also allows them to stay sharper longer. Identify this kit quickly among your tools with the easy-to-read description on the side of the case. The 21-Piece Titanium Coated Drill Bit Set includes bits in sizes 1/16 in. through 1/2 in. and a durable plastic case.