Unit 7 Flashcards
Aligned Dimension
A system of dimensioning which requires all numerals, figures, and notes to be aligned with the dimension lines so that they may be read from the bottom (for horizontal dimensions) and from the right side (for vertical dimensions).
Baseline Dimensioning System
System of dimensioning in which all dimensions are placed from a datum and not from feature to feature. Also referred to as Datum Dimensioning.
Chain Dimensioning
Also known as point-to- point dimensioning where dimensions are established from one point to the next.
Limit Dimensions
The largest and smallest possible boundaries to which a feature may be made as related to the tolerance of the dimension.
Location Dimension
A location dimension that defines the relationship of features of an object.
Reference Dimension
A dimension, usually without a tolerance, used for information purposes only. A reference is a repeat of a given dimension or established from other values shown on a drawing. Reference dimensions are enclosed in ( ) on the drawing.
Datum Dimensioning
A dimensioning system where each dimension originates from a common surface, plane, or axis. Also known as baseline dimensioning.
Unidirectional Dimension
A dimensioning system which requires all numerals, figures, and notes to be lettered horizontally and to be read from the bottom of the drawing sheet.
Tolerance
The acceptable amount of dimensional variation that will still allow an object to function correctly..
Nominal Size
The designation of the size established for a commercial product.
Bilateral Tolerance
A tolerance in which variation is permitted in both directions from the specified dimension.
Allowance
The tightest possible fit between two mating parts.
Clearance Fit
Limits the size of mating parts so that a clearance always results when mating parts are assembled.
Interference
The amount of overlap that one part has with another when assembled.
American National Standards Institute (ANSI)
A private, non-profit organization that coordinates the development and use of a voluntary consensus standards in the United States.
Technical Writing
A type of expository writing that is used to convey information for technical or business purposes.
American Society of Mechanical Engineers (ASME)
A professional engineering organization that is known for setting codes and standards for mechanical devices in the United States.
Parts List
A list of materials or parts specified for a project. Also referred to as a bill of materials or BOM.
International Organization for Standardization (IOS)
This is a worldwide organization that creates engineering standards.
Decision Matrix
A tool used to compare design solutions against one another, using specific criteria.
Market Research
The activity of gathering information about consumers’ needs and preferences.
Auxillary View
A view that is used to show features that are located on an inclined surface in true size and shape.
Section Lines
Thin lines used in a section view to indicate where the cutting plane line has cut through material.
Broken-out Section
A section of an object broken away to reveal an interior feature for a sectional drawing.
