ALPHABET OF LINES

• Visible Lines

  Also called Object Lines. Thick lines that show visible edges or contours of an object
• Hidden Lines


  Medium weight dashed lines used to show the hidden or invisible edges
• Center Lines


  Thin lines to show the centers of holes of circular object or shape
• Section Lines


  Medium lines to show a surface that has been cut in a section view, presumed to be solid portion
• Extension Lines


  Thin lines that indicate the limit of dimension line
• Dimension Lines


  Thin lines to show the size of an object, with one extension line to the next, arrowhead, and measurement number in the middle called Numerical Value
• Leader Lines


  Medium lines used to direct descriptive major information, notes, special dimensions to features, done mechanically
• Cutting-Plane Lines


  Thick lines to show where a section has been taken, with arrows on the end indicating the direction
• Break Lines


  Lines used to show the part of the object that has been removed or broken away, of two types: short break lines and long break lines
• Short Break Lines

  Thick, freehand, jagged lines applicable for small objects only
• Long Break Lines


  Thin, solid lines with a Z symbol inserted in several places, applicable for big objects only
• Reference Line


  Thin, irregular fine curve line with an arrowhead used for indicating measurement and name
• Phantom Line


  Thin line to indicate alternate positions of the parts of an object, repeated detail or locations of absent parts, with alternating one long and two evenly spaced, short dashes, and a long dash at each end
• ALPHABET OF LINES

  • refers to the line symbols used in technical drawing
• ALPHABET OF LINES

  • line features vary by width and graphically represented
• ALPHABET OF LINES

  • used to describe shape, size, hidden surfaces, interior detail, and alternate positions of parts.
• Technical Drawing is a form of design communication based on line symbols recognized and understood worldwide