43 terms

# Lesson 2.3 Key Terms

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Assembly
a group of machine parts that fit together to form a self-contained unit.
Balloons
A circled number identifying each part shown in an assembly drawing. Also called a ball tag or bubble number.
Broken-out Section
A section of an object broken away to reveal an interior feature for a sectional drawing.
Component
an artifact that is one of the individual parts of which a composite entity is made up
Countersink
a bit for enlarging the upper part of a hole
Degree of Freedom
(statistics) an unrestricted variable in a frequency distribution
Exploded Assembly
An assembly drawing in which parts are moved out of position along an axis so that each individual part is visible.
Full Section
A sectional drawing based on a cutting plane line that extends completely through an object.
Key
metal device shaped in such a way that when it is inserted into the appropriate lock the lock's mechanism can be rotated
Parameter
a quantity (such as the mean or variance) that characterizes a statistical population and that can be estimated by calculations from sample data
Parametric Modeling
A CAD modeling method that uses parameters to define the size and geometry of features and to create relationships between features. Changing a parameter value updates all related features of the model at once.
Rotation
a single complete turn (axial or orbital)
Section Lines
Lines that are used to represent the material through which a cut is made in order to show an interior sectional view.
Subassembly
An assembled part that is a part of a larger assembly.
Title Block
A table located in the bottom right-hand corner of an engineering drawing that identifies, in an organized way, all of the necessary information that is not given on the drawing itself. Also referred to as a title strip.
Assembly Drawing
A drawing that shows the various parts of an item when assembled.
Blind Hole
A hole that does not go completely through the workpiece.
Chamfer
A small angled surface formed between two surfaces.
Constraint
the state of being physically constrained
Cutting Plane Line
a line drawn on a view where a cut was made in order to define the location of the imaginary section plane.
Documentation
documentary validation
Foreshorten
shorten lines in a drawing so as to create an illusion of depth
Half Section
A sectional drawing based on a cutting plane line that cuts through one-quarter of an object. A half section reveals half of the interior and half of the exterior.
Keyseat
A slot in a shaft to receive a key.
Parts List
A list of materials or parts specified for a project. Also referred to as a bill of materials or BOM.
Ratio
the relative magnitudes of two quantities (usually expressed as a quotient)
Round
express as a round number
Sectional View
A drawing that shows the interior of an object as it would appear if cut in half or quartered.
Tap
draw from
Translation
the act of changing in form or shape or appearance
Auxiliary View
An orthographic view of an object using a direction of sight other than one of the six basic views (front, top, right-side, rear, bottom, left-side); used to show a surface that is not parallel to any of the principal view planes.
Break Line
A line used to interrupt a drawing if an object will not fit on a drawing sheet.
Clearance Fit
A group of values that is used to analyze the distribution of data.
Counterbore
a bit for enlarging the upper part of a hole
Detail Drawing
A dimensioned, working drawing of a single part. Also referred to as part drawing.
Formula
something regarded as a normative example
Interference
the act of hindering or obstructing or impeding
Keyway
A slot in a hub or material around a shaft that receives a key.
Phantom Line
A line used to show the alternate positions of an object or matching part without interfering with the main drawing.
Rib
a projecting molding on the underside of a vault or ceiling
Scale
size or measure according to a scale
Spotface
A shallow recess like a counterbore, used to provide a good bearing surface for a fastener.
Working Drawings
Drawings that convey all of the information needed to manufacture and assemble a design.