Product Description Professional contractors rely on DEWALT Spade Bits when they need to quickly bore clean holes for electrical, plumbing, framing and more. Featuring a heavy-duty, heat-treated shank for protection against bends and breaks, DEWALT Spade Bits are equipped with an optimized cutting groove which provides fast chip removal, and a ¼” ball groove shank offer easy quick changes in impact drivers. Chamfered corners boost durability especially against nail impacts. Available in sizes ranging from 1/4 in. to 1-3/8 in. Dia, available lengths 6" and 16". -- The DEWALT DW1587 6 Bit 3/8-Inch to 1-Inch Spade Drill Bit Assortment includes six commonly used high-performance drill bits to complement your tool set. The set features the Max Life corner that preserves nail life, the Extreme Speed Channel for efficient chip removal, and a 1/4-inch ball groove shank for quick bit changes. DEWALT spade bits are designed with heavy-duty shanks for extended life and durability. From the Manufacturer All DEWALT spade bits are designed with cutting spurs for optimum hole finish, a hang hole for bit storage & wire pulling, full length heat treat for longer life, flats on shank to prevent slipping in chuck, 1/4-inch Quick Change shank which fits all drills, and 1/4-inch quick change holders.