old_contents: #!/usr/bin/env python3
  """
  Thread information
  """
  from collections import namedtuple
  
  __all__ = ["ThreadParameters", "threads"]
  
  class ThreadParameters(namedtuple("ThreadParameters", ["pitch", "outer_diameter", "inner_diameter"]):
      """
      Parameters
      ==========
      pitch:
          Thread pitch in mm
      outer_diameter:
          Outside thread diameter in mm (for outside thread)
      inner_diameter:
          Inside thread diameter in mm (for outside thread)
      """
      pass
  
  threads = {
      # DIN 13
      # Source: http://www.gewinde-norm.de/metrisches-iso-gewinde-din-13.htm
      "M1": ThreadParameters(.25, 1., .693),
      "M1.2": ThreadParameters(.25, 1.2, .893),
      "M1.6": ThreadParameters(.35, 1.6, 1.171),
      "M2": ThreadParameters(.40, 2., 1.509),
      "M2.5": ThreadParameters(.45, 2.5, 1.948),
      "M3": ThreadParameters(.5, 3., 2.387),
      "M4": ThreadParameters(.7, 4., 3.141),
      "M5": ThreadParameters(.8, 5., 4.019),
      "M6": ThreadParameters(1., 6., 4.773),
      "M8": ThreadParameters(1.25, 8., 6.466),
      "M10": ThreadParameters(1.5, 10., 8.160),
      "M12": ThreadParameters(1.75, 12., 9.853),
      "M16": ThreadParameters(2., 16., 13.546),
      "M20": ThreadParameters(2.5, 20., 16.933),
      "M24": ThreadParameters(3., 24., 20.319),
      "M36": ThreadParameters(4., 36., 31.093),
      "M42": ThreadParameters(4.5, 42., 36.479),
      "M48": ThreadParameters(5., 48., 41.866),
      "M56": ThreadParameters(5.5, 56., 49.252),
      "M64": ThreadParameters(6., 64., 56.639)
  ]
new_contents: #!/usr/bin/env python3
  """
  Thread information
  """
  from collections import namedtuple
  
  __all__ = ["ThreadParameters", "threads"]
  
  class ThreadParameters(namedtuple("ThreadParameters", ["pitch", "outer_diameter", "core_diameter"])):
      """
      Parameters
      ==========
      pitch:
          Thread pitch in mm
      outer_diameter:
          Outside thread diameter in mm (for exterior thread)
      inner_diameter:
          Inside thread diameter in mm (for exterior thread)
      """
      pass
  
  threads = {
      # DIN 13
      # Source: http://www.gewinde-norm.de/metrisches-iso-gewinde-din-13.htm
      "M1": ThreadParameters(.25, 1., .693),
      "M1.2": ThreadParameters(.25, 1.2, .893),
      "M1.6": ThreadParameters(.35, 1.6, 1.171),
      "M2": ThreadParameters(.40, 2., 1.509),
      "M2.5": ThreadParameters(.45, 2.5, 1.948),
      "M3": ThreadParameters(.5, 3., 2.387),
      "M4": ThreadParameters(.7, 4., 3.141),
      "M5": ThreadParameters(.8, 5., 4.019),
      "M6": ThreadParameters(1., 6., 4.773),
      "M8": ThreadParameters(1.25, 8., 6.466),
      "M10": ThreadParameters(1.5, 10., 8.160),
      "M12": ThreadParameters(1.75, 12., 9.853),
      "M16": ThreadParameters(2., 16., 13.546),
      "M20": ThreadParameters(2.5, 20., 16.933),
      "M24": ThreadParameters(3., 24., 20.319),
      "M36": ThreadParameters(4., 36., 31.093),
      "M42": ThreadParameters(4.5, 42., 36.479),
      "M48": ThreadParameters(5., 48., 41.866),
      "M56": ThreadParameters(5.5, 56., 49.252),
      "M64": ThreadParameters(6., 64., 56.639)
  }
  
subject: Improve thread naming