code: def get_drill_bits_d_imperial():
      
      step_32nd = np.arange(0.03125, 0.25, 0.03125)
      step_8th = np.arange(0.25, 1.0, 0.125)
      step_4th = np.arange(1.0, 2.0, 0.25)
      maximum = [2.0]
  
      return np.concatenate((step_32nd,
                             step_8th,
                             step_4th,
                             maximum)) * u.inch
docs: Return array of possible drill diameters in imperial.