An orbital drill includes a drilling portion, a shank portion, and a neck portion between the drilling portion and the shank portion. The drilling portion includes one or more right-handed spiral flutes with cutting edges having a positive axial rake angle for positive cutting action while orbiting into a material. The right-handed spiral flutes have a positive radial and axial rake angle. The drilling portion also includes one or more left-handed spiral flutes located rearward of the one or more right-handed spiral flutes with cutting edges having a positive axial and radial rake angle for positive cutting action while orbiting back out of the material and removing any material left in the hole, thereby eliminating a separate reaming operation. A method of machining a workpiece using the orbital drill is also disclosed.

An orbital drill includes a drilling portion, a shank portion, and a neck portion between the drilling portion and the shank portion. The drilling portion includes one or more right-handed spiral flutes with cutting edges having a positive axial rake angle for positive cutting action while orbiting into a material. The right-handed spiral flutes have a positive radial and axial rake angle. The drilling portion also includes one or more left-handed spiral flutes located rearward of the one or more right-handed spiral flutes with cutting edges having a positive axial and radial rake angle for positive cutting action while orbiting back out of the material and removing any material left in the hole, thereby eliminating a separate reaming operation. A method of machining a workpiece using the orbital drill is also disclosed.

Disclosed is an automated drill apparatus composed of one or more gang drills mounted to a gang drill chassis, at least one powered drive wheel affixed to the gang drill chassis, and at least three pivotable support wheels. A control panel provides remote operation of drill rotation activation, drill advance, and drill bed position adjustment, and a panic off switch. A control system implements steering the automated drill apparatus and is selectable by the operator for steering in two-wheel mode or crab steer mode. The pivotable drive wheels, in conjunction with the control panel and control system, are used to position the automated drill apparatus along a slab to be drilled, and further activate one or more gang drills for drilling a slab.