Rigid Right Angle Drill

right angle
An angle of 90°, as in a corner of a square or at the intersection of two perpendicular straight lines
the 90 degree angle between two perpendicular lines
In geometry and trigonometry, a right angle is an angle that bisects the angle formed by two halves of a straight line. More precisely, if a ray is placed so that its endpoint is on a line and the adjacent angles are equal, then they are right angles.
An angle of 90 degrees; the bisect of the angle formed by a single straight line

rigid
Unable to bend or be forced out of shape; not flexible
(of a person or part of the body) Stiff and unmoving, esp. as a result of shock or fear
incapable of or resistant to bending; "a rigid strip of metal"; "a table made of rigid plastic"; "a palace guardsman stiff as a poker"; "stiff hair"; "a stiff neck"
inflexible: incapable of adapting or changing to meet circumstances; "a rigid disciplinarian"; "an inflexible law"; "an unbending will to dominate"
Not able to be changed or adapted
incapable of compromise or flexibility

drill
a tool with a sharp point and cutting edges for making holes in hard materials (usually rotating rapidly or by repeated blows)
bore: make a hole, especially with a pointed power or hand tool; "don't drill here, there's a gas pipe"; "drill a hole into the wall"; "drill for oil"; "carpenter bees are boring holes into the wall"
similar to the mandrill but smaller and less brightly colored