AutoCAD and Its Applications BASICS Reference Material Glossary of CAD Terms 1D unit block: A 1-unit, one-dimensional aligned dimensioning: A dimensioning object, such as a straight line segment, system in which dimension values align saved as a block. with dimension lines. 2D unit block: A 2D object that fits into a aligned section: Section used when 1-unit × 1-unit square, saved as a block. a feature is out of alignment with the center plane. 3D unit block: A 3D object that fits into a 1-unit × 1-unit × 1-unit cube, saved as a alignment parameter: A parameter that block. aligns a block with another object in the drawing. alignment paths: Temporary lines and A arcs that coincide with the position of existing objects. absolute coordinates: Coordinate alternate units (dual dimensioning distances measured from the origin. units): Dimensions in which measurements in one system, such absolute path: A path to a file defined by as inches, are followed by bracketed the location of the file on the computer measurements in another system, such as system. millimeters. absolute value: In property settings, a angular dimensioning: A method of value set directly instead of referenced by a dimensioning angles in which one corner layer or a block. An absolute value ignores of an angle is located with a dimension the current layer settings. and the value of the angle is provided in acquired point: A point found by moving degrees. the crosshairs over a point on an existing annotation: Textual information presented object to reference the point when picking in notes, specifications, comments, and a new point. symbols. action: A definition that controls how annotational format: A dimensional dynamic block parameters behave. constraint format in which the constraints action bars: Toolbars that allow you to look like traditional dimensions, using a view, remove, and adjust actions. dimension style. Annotational dimensional constraints can still control the size or action parameter (parameter): A location of geometry. specification for block construction that controls block characteristics such as annotation scale: The scale AutoCAD positions, distances, and angles of dynamic uses to calculate the scale factor applied to block geometry. annotative objects. alert: A pop-up that indicates a required annotative object representation: Display action or potential problem. of an annotative object at an annotation scale that the object supports. Copyright Goodheart-Willcox Co., Inc. Glossary of CAD Terms 1 May not be reproduced or posted to a publicly accessible website. annotative objects: AutoCAD objects that B can adapt automatically to the current drawing scale. annotative text: Text scaled by AutoCAD background mask: A mask that hides a according to the specified annotation scale. portion of objects behind and around text so that the text is unobstructed. arc: Any portion of a circle, usually dimensioned according to the radius (R). balloons: Circles that contain a number or letter to identify the assembly component archiving: Gathering and storing all and correlate the component to a parts list drawings and associated files related to a or bill of materials. Balloons connect to a project. component with a leader line. array: Multiple copies of an object base dimension: The dimension line that arranged in a pattern. remains in the same location, with which array action: An action used to array other dimension lines align or space. objects within the block based on preset baseline dimensioning: A method of specifications. dimensioning in which several dimensions associated list: The ASME term describing originate from a common surface, tables added or related to engineering centerline, or center plane. drawings. base point: The initial reference point associative array: An adjustable array AutoCAD uses when stretching, moving, object; all items are grouped to form copying, and scaling objects. a single object, allowing you to make base point parameter: A parameter that modifications such as changing the number defines an alternate base point for a block. of items and spacing between items. basic dimension: A theoretically perfect associative dimension: A dimension dimension used to describe the exact associated with an object. The dimension size, profile, orientation, and location of a value updates automatically when the feature. object changes. big font: A supplement that provides associative hatch pattern: A hatch pattern Asian and other large-format fonts that that updates automatically when you edit have characters and symbols not present in associated objects. other font files. attachment: An xref linked with or bilateral tolerance: A tolerance style that referenced into the current drawing. permits variance in both the positive and attributes: Text-based data assigned to a negative directions from the specified specific object. Attributes turn a drawing dimension. into a graphical database. bind: Convert an xref to a permanently auto-fill: A table function that fills selected inserted block in the host drawing. cells based on the contents of another cell. block: An object, such as a symbol, saved automatic save: A save procedure that and stored in a drawing for future use. occurs at specified intervals without block definition: Information about a your input. block stored within the drawing file. automatic windowing (implied block insertion tools: Blocks located on a windowing): A selection method that tool palette. allows you to select multiple objects at one time without entering a selection option. block properties table: A table of action parameters and/or constraint parameters auxiliary view: View used to show the that allows you to create multiple block true size and shape of a foreshortened properties and then select them to create surface. block references. Copyright Goodheart-Willcox Co., Inc. Glossary of CAD Terms 2 May not be reproduced or posted to a publicly accessible website. block reference: A specific instance of a check box: A selectable box that turns block inserted into a drawing. an item on (when checked) or off (when unchecked). boundary: The area filled by a hatch. child: A style override. boundary edge: The edge to which objects such as lines, arcs, and polylines extend. chord length: The linear distance between two points on a circle or arc. boundary set: The part of the drawing AutoCAD evaluates to define a boundary. circle: A closed curve with a constant radius (R) around a center point; broken-out section: Section that shows a usually dimensioned according to the small portion of the object removed. diameter (∅). BSI: British Standards Institution. circular reference error: An error that button: A “hot spot” button on the screen occurs when a block definition references that you pick to access an application, itself. command, or option. circumscribed polygon: A polygon drawn outside an imaginary circle so that the sides of the polygon are tangent to the C circle. coincident: A geometric construction that callout block: A block that uses attributes specifies two points sharing the same containing fields that link the view position. number and sheet title between the sheet color-dependent plot style table: A file set and drawing (sheet) views. that contains plot style settings used to Cartesian (rectangular) coordinate assign plot values to object colors. system: A system that locates points in command: An instruction issued to the space according to distances from three computer to complete a specific task. For intersecting axes. example, use the LINE command to draw cascading menu (cascading submenu): line objects. A menu of options related to the chosen command alias: Abbreviated command menu item. name entered at the keyboard. cell styles: Styles that allow you to assign command line: Area where you can type specific formatting to data, header, and commands (command names) and type or title row cells. select command options. centroid: The mathematical center of a Commercial and Government Entity geometric figure. Code (CAGE Code): A five-digit chain action: An action that triggers numerical code identifier applicable to any another action when you modify a organization that produces items used by parameter. the federal government. chain dimensioning: A method of composition: The spacing, layout, and dimensioning in which dimensions appear appearance of text. in a line from one feature to the next. computer-aided design and drafting chamfer: In mechanical drafting, a small, (CADD): The process of using a computer angled surface used to relieve a sharp corner. with CADD software to design and produce drawings and models. chart dimensioning: A type of dimensioning in which the variable concentric: Describes arcs, circles, and/or dimensions are shown with letters that ellipses sharing the same center point. correlate to a chart in which the possible configured: Installed and ready to use. dimensions are given. Copyright Goodheart-Willcox Co., Inc. Glossary of CAD Terms 3 May not be reproduced or posted to a publicly accessible website. constant: An expression or value that stays current layer: The active layer. Whatever the same. you draw is placed on the current layer. constraint parameters: Dimensional curve fitting: Converting a polyline into a constraints available for block construction series of smooth curves. to control the size or location of block cutting edge: An object such as a line, geometry numerically. arc, or text that defines the point (edge) at construction lines: Lines commonly used which the object you trim will be cut. to lay out a drawing. cutting-plane line: The line that cuts context-oriented help: Help information through the object to expose internal for the active command. features. context-sensitive: Specific to the active cycle: Repeatedly select a series of command or option. stacked objects until the desired object is highlighted. continued dimensioning: The AutoCAD term for chain dimensioning. control code sequence: A key sequence D beginning with %% that defines symbols in text. control vertices: Points that are used to datum: Theoretically perfect surface, define the curve shape and change the curve plane, point, or axis from which design.