Ground from solid 1 piece design and is up to 5X more durable. Web tapered increases the rigidity of the bit to decrease the potential for bit breakage. Pilot point tip allows users to drill holes faster and offers clean burr-free holes. Common users include electricians, HVAC, mechanic, glaziers and General contractors. Designed for metal or wood. 1/4 in hex shank. Set includes two 1/8 in bits, one 5/32 in bit, one 3/16 in bit, one 7/32 in bit, one 1/4 in bit and one 5/16 in bit.