| A | B |
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| Aligned System | The System of Dimensioning that applies the figures to be read from the bottom or the right side position. |
| Alphabet of Lines | The variety of lines used to describe objects and their relationships within a drawing. |
| Architects Scale | A measurement scale that uses fractions of an inch as small as 1/32 of an inch. It also has other reduced scales for the conversion of sizes where inches or fractions of an inch=feet. |
| Arrowhead | The pointer on the end of a dimension line. |
| Assembly Drawing | A drawing that shows how part or all of a machine or structure is put together. |
| Auxiliary View | A true size view of some object shown by projecting perpendicular to the face of the auxiliary view. |
| Axis | A line that represents the center of some object usually used for rotation about that object. |
| Basic Size | The size from which the limits of a size are derived. It is used to determine allowances and tolerances. |
| Bevel | An inclined edge, not at a right angle to a surface. |
| Blind Hole | A hole that does not go through a solid piece. |
| Bolt Circle | A circular centerline in a drawing that contains the centers of holes about a common center. |
| Bore | A method to enlarge a hole to a specific precise size. |
| Broach | A long cutting tool with a series of progressively larger teeth that when forced into a hole will change the shape and size. It may be square, triangular, hexagonal or octagonal. |
| Broken-out Section | A small part of a view that is sectioned to show some inside detail. |
| Cam | A rotating part that changes rotating motion into reciprocating motion. |
| Center line | A line that is used to represent an axis of symmetry. Always used for circles and arcs to locate their centers. |
| Chamfer | A narrow inclined surface along the intersection of two adjacent surfaces. |
| Cone | A single-curved surface that has straight line elements. |
| Coordinates | Numbers that relate to the intersection of three planes, the X,Y plane. the Y,Z plane and the X,Z plane. They are always expressed as X,Y,Z. In two dimensional drawings the Z-coordinate is usually omitted. French mathematician Renée Decartes is credited with developing the Cartesian Coordinate system |
| Conventional Break | A method used to remove a considerable length from a long object where there is no change over that length. |
| Counterbore | A square bottomed hole larger in diameter than a hole with the same center, usually for a hexagon socket head screw. |
| Countersink | The process of enlarging a hole conically, usually for a flat head screw. |
| Cutting-plane line | A line that represents an edge that intersects an adjacent plane at a perpendicular angle. |
| Cylinder | A Solid or tubular curved surface that has length and diameter. |
| Detail Drawing | A drawing that gives all of the information necessary to construct some part or part a a larger structure. |
| Development | The drawing of the surface of an object as if it were unfolded or rolled out onto a plane. |
| Dimension line | A line that shows where some detail is measured. It has three components, the line, arrowhead(s), and the measurement. |
| Drill | The process of removing material to make a hole in some material, it is equal to the diameter of the hole. |
| Edge view | The view of a plane obtained by looking parallel to a true length line in the surface. |
| Ellipse | The geometric form that resembles a circle when viewed at some angle to its edge. |
| Engineers Scale | A series of measurement scales in which inches are divided into 10, 20, 30, 40, 50, 60 or 80 parts. It is used to draw large parts in a small area. |
| Entities | The basic geometric shapes like lines, circles and arcs that make up objects in a CAD drawing. |
| Extension Line | A line or lines that extend from an object to help better portray a dimension by eliminating clutter and crowding next to the object being dimensioned. |
| Face | A plane surface of an object. A process that produces a finish on a surface perpendicular to a centerline of rotation. |
| FAO | Finish All Over |
| Fillet | An interior rounded intersection between two adjacent surfaces. |
| Finish Mark | A symbol that designates a surface or face of an object that must be smooth to some degree of precision. |
| Fit | The degree of tightness or looseness between two mating parts. |
| Flange | A thin rim around a circular part. |
| Front View or Elevation | A view that shows the true width and height of an object. |
| Full Section | A sectional view obtained by passing a cutting plane completely through an object. |
| Grid | A horizontal and vertical pattern of dots equally spaced to assist in the process of drawing. |
| Half Section | A sectional view obtained by passing a cutting plane completely through an object but showing only one half of that view. |
| Half View | A view sometimes used for symmetrical objects. Centerlines show the lines of symmetry, thus allowing only half of the view to describe a full object. |
| Height | The distance from the bottom of some part to the top of that part, perpendicular to the bottom. |
| Hidden Line | A dashed line that represents an edge or surface that cannot be seen in the view. |
| Icon | A small picture that is a symbol used to select a CAD/Computer tool. |
| Inclined | A slanted line that is not perpendicular to one to of the planes. |
| Isometric Drawing | A type of drawing in which the lower edges are drawn at 30 degrees from a horizontal, all vertical edges are perpendicular to horizontal. |
| Joints | The points where edges and surfaces of solid objects meet. |
| Key | A piece of metal that prevents a shaft and hub from rotating at different speeds. |
| Keyseat | The groove in a shaft that hold a key in place. |
| Keyway | The groove in a hub that holds a key in place. |
| Knurl | A pattern of shallow grooves and bumps that permit a better grip on a cylindrical part. |
| Layer | An electronic sheet of paper that allows different parts of a drawing to be visible or invisible, colored, or of different linetype. |
| Leader | A thin solid line that is drawn from some note to its detail on an object. |
| Machine Drawing | Technical drawing used for the machine tool and manufacturing industries. |
| Major Axis | The long axis of an ellipse. |
| Major Diameter | The largest diameter of a threaded part. |
| Mating Parts | Two of more parts that must fit together. |
| Menu | A list of items or commands in a CAD/Computer program application. |
| Metric System | A decimal system of measurement based on the meter. |
| Mill | A process of removing material with a rotating cutter. |
| Minor Axis | The short axis of an ellipse. |
| Minor Diameter | The smallest diameter of a threaded part. |
| Nominal Size | The size used for general identification on a part. |
| Non-isometric Lines | Lines that art not parallel to the isometric axes. |
| Object Snap | A feature in CAD programs that allows the user to automatically jump to specific points on an object. |
| Offset Section | A sectional view in which the cutting plane is bent to pass through several different features not inline. |
| One-point perspective | A type of perspective drawing that has one vanishing point. |
| Ortho | A feature in CAD programs that restricts the placement of lines to vertical or horizontal. |
| Orthographic | A series of views of an object that are aligned horizontally and vertically. The top view is directly over the front view and the side views are aligned to each other. |
| Parallel Line Development | A rectangular pattern that is produced when a prism or cylinder is rolled out. |
| Partial View | A view that gives some shape and size description without describing a whole view of the drawing. |
| Perspective | A technique of drawing that shows the parts of an object that are closer to the viewer larger and parts that are further away smaller. |
| Pictorial Drawing | A type of drawing that shows multiple faces of an object as they might appear in real life. |
| Plan view | A top view in an Architectural Drawing. |
| Primary Auxiliary Views | The first auxiliary view projected from the principal views of an object. |
| Profile | An outline or sectional view produced by a vertical sectioning plane. |
| Pyramid | A geometric shape created by the intersections of the edges of triangular shapes. |
| Quadrilateral | A geometric shape having four sides. |
| Radial Line Development | A development in which the edges radiate from a point that may or may not be on the object. |
| Rapid Prototyping | A process that creates a physical model from a 3D CAD drawing. |
| Ream | The process of enlarging a hole to a precise size. |
| Removed Section | A sectional view that is moved from its normal position to better describe that view, it may be drawn in a larger scale. |
| Revolved Section | A sectional view that represents a view at a right angle to the views actual position. |
| Rib or Web | A thin flat part of an object that is used to add strength to an object and reduce weight. |
| Right-side View | A view that shows the true height and depth of an object. |
| Round | An exterior curved edge of an object. |
| Schedule | A table or chart on a drawing that provides a place for specifications as well as part and detail information. |
| Schematic | An electrical or electronic part drawing. |
| Secondary Auxiliary View | An auxiliary view that is produced from one of the primary auxiliary views of an object. |
| Section | A cutaway view of an object. |
| Slope | The true angle between a line and horizontal. |
| Snap | A feature in CAD programs that allows the user to automatically connect to preset points. |
| Specifications | Written documents that detail special properties of an object or series of drawings. |
| Sphere | A solid geometric figure whose points are all equidistant from the center. |
| Spline | A series of keyways cut about a shaft and mating hole. |
| Spotface | A process that produces a smooth finish perpendicular to the longitudinal centerline of a hole. |
| Tap | The process of producing threads in a hole. |
| Tapped Hole | A threaded hole |
| Template | A pattern or drawing that has special features completed for repetition . |
| Tolerance | The total amount of variation permitted on the details of a part of a drawing. |
| Torus | A geometric shape resembling a doughnut. It has an inside diameter, outside diameter and tubular radius. |
| Triangle | A plane figure that has three sides and three angles. It may be Equilateral(all sides and angles equal), Isosceles(two equal sides and angles) or a Right(one 90 degree angle)Triangle. |
| Trim | A feature in CAD programs that allows the user to easily erase part of a line that intersects another. |
| Turn | The machine process that provides cylindrical parts. |
| Two-point Perspective | A perspective drawing that has two vanishing points. |
| Unidirectional System | A dimensioning system that allows all figures and dimensions to be read from the bottom of the sheet. |
| View | A drawing that shows an object from one position and the true length and size. The Primary views are the Top, Front and Right Side. |
| Web or Rib | A thin flat part of an object that is used to add strength to an object and reduce weight. |
| Weld | The process of joining metals by heating them to their melting point with or without pressure. |
| Woodruff Key | A semicircular flat key. |
| Working Drawing | A complete drawing or series of drawings that have been prepared to provide all of the information necessary to build the product. |
