An economical alternative to reamers, these sets include four bit sizes for enlarging existing drilled holes. Bits have four flutes that won’t catch on the inside of the hole like standard two-flute bits can, avoiding damage to the hole and your tool. The shank has a smaller diameter than the cutting tip, so you can ream large holes using tools that have small-capacity chucks. Sets also contain four hole-starting bits.

One cobalt bit drills multiple hole sizes and lasts twice as long as high-speed steel. They have steps with progressively larger diameters—the deeper they drill, the bigger the hole. Count the steps as you drill to achieve the proper size. These bits also deburr as they cut, so they're good for thin materials like sheet metal and plastic panels. Wear and heat resistant, high-speed steel is versatile for use on a range of materials.

Tough and wear resistant, cobalt steel bits last at least twice as long as high-speed steel. They can also run up to 25% faster at higher temperatures without being damaged on hard materials, such as nickel.