Blueprint Reading 131

The class “Blueprint Reading” provides a thorough understanding of blueprints and how to read them. Blueprints are documents that contain three major elements: the drawing, dimensions, and notes. The drawing illustrates the views of the part necessary to show its features. Together, the extension and dimension lines on the drawing indicate dimensions and specific tolerance information of each feature. The notes contain administrative and global information about the part. A blueprint contains all instructions and requirements necessary to manufacture and inspect a part.

An understanding of how to read a blueprint is critical to manufacture and inspect parts to accurate specifications. Accurate blueprint creation helps to ensure that finished parts will function in a way that meets the original intent. After taking this class, users should be able to read a basic blueprint and determine the critical features on a part that need to be measured.

Class Details

Class Name:
Blueprint Reading 131
Description:
The class “Blueprint Reading” provides a thorough understanding of blueprints and how to read them. Blueprints are documents that contain three major elements: the drawing, dimensions, and notes. The drawing illustrates the views of the part necessary to show its features. Together, the extension and dimension lines on the drawing indicate dimensions and specific tolerance information of each feature. The notes contain administrative and global information about the part. A blueprint contains all instructions and requirements necessary to manufacture and inspect a part.

An understanding of how to read a blueprint is critical to manufacture and inspect parts to accurate specifications. Accurate blueprint creation helps to ensure that finished parts will function in a way that meets the original intent. After taking this class, users should be able to read a basic blueprint and determine the critical features on a part that need to be measured.
Version:
2.0
Difficulty:
Beginner
Number of Lessons:
16
Related 1.0 Class:
Blueprint Reading 130

Class Outline

  • What is a Blueprint?
  • Blueprint Contents
  • Orthographic Views
  • Auxiliary and Section Views
  • Types of Section Views
  • Object and Hidden Lines
  • Extension, Dimension, and Leader Lines
  • Center, Break, and Phantom Lines
  • Cutting Plane and Section Lines
  • Line Variety in Part Views
  • Blueprint Dimensions
  • Types of Dimensions
  • Uses of Dimensions
  • The Title and Change Blocks
  • Use of Scale and Tolerances
  • Section Review

Objectives

  • Define blueprint. Identify the three basic elements of a blueprint.
  • Explain what an orthographic view is and the six possible basic views.
  • Distinguish between auxiliary and section views.
  • Identify the types of section views.
  • Describe how to show part edges.
  • Identify how to indicate dimensions.
  • Describe the appearance and use of center, break, and phantom lines.
  • Identify how section views are displayed.
  • Identify the dimensions on a blueprint.
  • Describe descriptive dimensions.
  • Describe functional dimensions.
  • Describe the appearance and use of notes.
  • Explain how to use scale and tolerance information on a print.

Certifications

Glossary

Vocabulary Term Definition
auxiliary view A blueprint view drawn at a right angle to an angled feature of a part. Auxiliary views provide a full straight-on picture of an angled side that cannot be fully represented with a basic orthographic view.
blueprint A document that contains all the instructions for a particular part and communicates all requirements necessary to manufacture and inspect a quality part. There are three main elements of a blueprint: the views, their dimensions, and the notes.
break lines A line used to define the boundary of an imaginary broken-out section or to shorten dimensions that are excessively long. Break lines are wavy and irregular.
broken-out section A section view resulting from an imagined cut that removes a small portion of the part exterior to reveal the features beneath. Broken-out sections are used to highlight small details.
center lines A line used to define a cylindrical or symmetrical feature or part. Center lines consist of alternating long and short dashes.
change block The area of the blueprint indicating any changes or revisions made to the part views or dimensions. Change blocks should contain every revision, as well as the dates in which those revisions were made.
cutting plane line A line in a blueprint that represents the path and position of an imaginary cut made to form a sectional view. Cutting planes are made up of a long dash, followed by two short dashes that are slightly thicker than a phantom line.
dimension line A line used to define the measurement of a part feature. Dimension lines consist of a solid line with arrows at both ends and a dimension in the center.
dimensions The desired measurement of a feature on a part. A dimension is listed as a number given in the appropriate units.
extension line A line used to visually connect the ends of a dimension line to the relevant feature on a part. Extension lines are solid and drawn perpendicular to the dimension line.
full section A section view in which the part is cut entirely in half. The right side is removed and presented cut-side up.
half section A section view in which an imaginary cut is made through the part and half of that cut is presented cut-side up. Symmetrical parts often contain half sections.
hidden line A line used to define a part feature that is not visible in a specific view. Hidden lines consist of a series of short dashes.
isometric view A drawing that communicates the shape and size of an object in three dimensions by showing three sides of the object from one perspective. Isometric views are not frequently utilized in blueprints.
leader line A thin line ending in an arrow used to tie a dimension to a feature. Leader lines are used when there are space limitations in a view.
notes An additional instruction or general comment added to a blueprint. Notes contain information about the material, finish, tooling, tolerances, and other miscellaneous information.
object line A line used to define the shape and size of a part feature and represent the visible edges of the part. Object lines are solid.
offset section A section view resulting from an imagined cut resulting from a line that has segments which turn at 90 degrees, with both end segments going in the same direction. Offset sections allows features to be shown that don’t occur in a straight line.
offset section A section view resulting from an imagined cut resulting from a line that has segments which turn at 90 degrees, with both end segments going in the same direction. Offset sections allows features to be shown that don't occur in a straight line.
orthographic views A drawing often used for blueprints that communicates the shape and size of an object in two dimensions. Orthographic views allow for a clear image of all the design elements of a part through a series of illustrations each showing one of its necessary sides from a continuous perspective.
phantom lines A line that indicates the alternative positions of a feature that moves, repeated details, or material that will be machined from the part at some stage of the manufacturing process in a blueprint. A phantom line is drawn by alternating a long dash, followed by two short dashes that are thinner than a cutting plane line.
reference dimensions A dimension that is provided for informational purposes only. Reference dimensions appear in parentheses or are marked with "REF."
removed section A section view resulting from an imagined cut that removes and rotates a slice taken from the middle of a part feature. Removed sections are sometimes used to show an enlarged area of a part too small to be illustrated clearly on the original view.
repetitive dimensions A dimension that is assumed to be the same for similar features of a part. After the dimension, the number of repetitions is given, followed by an X or "PLACES."
revolved section A section view resulting from an imagined cut that separates the middle of the part feature and rotates a slice taken from that cut in place. Revolved sections have section lines and show the true shape of a part.
scale The area of the blueprint indicating the relationship between the drawing size and the actual part size. Scale is expressed as a ratio, with the drawing number first.
section line A line used to identify the imaginary cut portion of a part in a section view. Section lines appear as a series of diagonal lines drawn close together at a 45-degree angle.
section view A view illustrating a rotated section resulting from an imaginary cut in the part. Blueprints may contain a variety of different section views.
title block The area of a blueprint containing information such as company name, part name, part number, designer, scale, and material. Title blocks are unique to each manufacturer.
tolerances An unwanted but acceptable variation or deviation from a desired dimension of a part. The object will still meet specifications.
typical dimensions A dimension that is assumed to be the same for similar features of a part. Typical dimensions are marked with "TYP."
views Consists of all the lines that illustrate the shape of the part. A blueprint often contains multiple views to convey all of a part's design elements.