This .NET class wraps the AcDb::LineWeight ObjectARX enumerated type. 

This enumerated type provides the line weight (thickness) values used to specify how lines will be displayed and plotted. The lineweights are in 100ths of a millimeter, except for the negative values. The negative values denote the default indicated by their constant's name.

Public Enum LineWeight
  ByBlock = -2
  ByDIPs = -4
  ByLayer = -1
  ByLineWeightDefault = -3
  LineWeight000 = 0
  LineWeight005 = 5
  LineWeight009 = 9
  LineWeight013 = 13
  LineWeight015 = 15
  LineWeight018 = &H12
  LineWeight020 = 20
  LineWeight025 = &H19
  LineWeight030 = 30
  LineWeight035 = &H23
  LineWeight040 = 40
  LineWeight050 = 50
  LineWeight053 = &H35
  LineWeight060 = 60
  LineWeight070 = 70
  LineWeight080 = 80
  LineWeight090 = 90
  LineWeight100 = 100
  LineWeight106 = &H6a
  LineWeight120 = 120
  LineWeight140 = 140
  LineWeight158 = &H9e
  LineWeight200 = 200
  LineWeight211 = &Hd3
End Enum

public enum LineWeight {
ByBlock = -2,
ByLayer = -1,
ByLineWeightDefault = -3,
LineWeight000 = 0,
LineWeight005 = 5,
LineWeight009 = 9,
LineWeight013 = 13,
LineWeight015 = 15,
LineWeight018 = 0x12,
LineWeight020 = 20,
LineWeight025 = 0x19,
LineWeight030 = 30,
LineWeight035 = 0x23,
LineWeight040 = 40,
LineWeight050 = 50,
LineWeight053 = 0x35,
LineWeight060 = 60,
LineWeight070 = 70,
LineWeight080 = 80,
LineWeight090 = 90,
LineWeight100 = 100,
LineWeight106 = 0x6a,
LineWeight120 = 120,
LineWeight140 = 140,
LineWeight158 = 0x9e,
LineWeight200 = 200,
LineWeight211 = 0xd3
}