Precision Twist Drill Parabolic flute drill bits, these have a large flute space for greater chip flow and improved coolant flow to the drill bit point. These factors allow bits to drill deeper and produce closer hole tolerances more quickly than regular jobbers bits. A large cross section increases rigidity and strength. Bits have a reduced margin width to lessen contact between the bit and the hole sides to minimize friction and heat. A self centering 135 degree split point penetrates faster than other point styles, produces smaller chips for better chip flow, and will not skip or walk when starting a hole. The shank diameter is the same as the drill bit size.