| A | B |
|---|
| Acute Angle | An angle of less than 90 degrees. |
| Alloy | Two or more metals in combination. |
| Allowance | Minimum clearance or maximuminterferance between mating parts. |
| Angle | A space fromed by the intersection of two lines or planes. |
| Arc | Part of a circle. |
| Architect | A person who designs and oversees the construction of buildings. |
| Area | The amount of surface contained wihtin a figure. |
| Arrowheads | Point used on the end of dimension lines or leaders. |
| Assembly drawing | A drawing showing all the parts in their proper locations. |
| Basic size | The size of an object from which tolerances are applied. |
| Bearing | A supporting member for a rotating shaft. |
| Bevel | An inclined edge, not a right angle to a joining surface. |
| Bisect | To divide in to equal parts. |
| Blueprint | A reproduction of a drawing having a bright blue background and white lines. |
| Bolt circle | A circular center line on which holes are located. |
| Bore | To enlarge a hole with a boring bar or other machine tool. |
| Cam | A rotating member used to change circular motion to reciprocating motion. |
| Casting | An object made by pouring molten metal in to a mold. |
| Center line | A thin line representing the center of holes or the axis of cylindrical objects. |
| Chamfer | A slight bevel on the end of a shaft or corner of an object to avoid a sharp edge. |
| Circumference | The perimeter of a circle. |
| Civil Drafter | A person who prepars draeings dealing with highways, bridges, tunnels, and so on. |
| Clearance fit | Class fit where clearance is always maintained between mating parts. |
| Collar | A round flange or ring fitted to a shaft to prevent sliding. |
| CAD | Computer aided drafting |
| Concave | Curved depression in a surface |
| Concentric | Having the same centers. |
| Cone | Geometric shape that tapers uniformly from a point to a circular base. |
| Conical | Shaped like a cone. |
| Convex | Exterior rounded surface of an object |
| Core | To form a hollow area in a part to be cast in a mold. |
| Counterbore | To enlarge the end of a hole cylindrically to a given depth. |
| Countersink | To enlarge the end of a hole to a specified angle. |
| Crosshatching | Lines added to a sectional drawing to indicate the material of the part. |
| Cylinder | A geometric figure having a uniform circular cross-section fo its entire length. |
| Detail drawing | Drawing of a single part including its exact dimensions. |
| Development | Drawing of the surface of an object unfolded or rolled out on a plane. |
| Diagonal | A line running across a figure from opposite corners. |
| Diameter | Distance across a circle. |
| Dimension line | Line drawn between extension linesthat contains a size dimension. |
| Dowel | A cylindrical pin used primarily to prevent sliding between two contacting surfaces. |
| Drafter | A person who works with original designs to make production drawings. |
| Drill | To cut a cylindrical hole using a drill bit. |
| Eccentric | Not having a common center. |
| Ellipse | An oval circular figure with two centers and a major and minor axis. |
| Engineer | A person who solves technical problems for a company. |
| Entity | A point, line, arc, circle, or text used to generate CAD drawings. |
| Equilateral triangle | A triangle having all sides and angles equal. |
| Erasing shield | A grafting aid used to protect specific features when erasing. |
| Extension lines | Thin lines drawn from object lines to indicate where dimensions begin and end. |
| Fillet | The inside rounded casting on a casting. |
| Fit | The degree of looseness or tight ness between two mating parts. |
| Flange | A relatively thin rim around an object. |
| Floor plan | Top view of a building at a specified floor level. |
| Full section | View of an object that is cut in half by a cutting-plane with the front half removed. |
| Galvanize | To cover a surface with a molten alloy to prevent rusting. |
| Gasket | Thin piece of material placed between two surfaces to make a tight joint. |
| Graphic symbols | Symbolic representations used to simplify complicated items. |
| Half-section | View of an object in which one quarter of the object has been removed. |
| Hexagon | Six-sided geometric shape. |
| Hidden line | Thin line made up of a series of short dashes showing a surface that is hidden behind other surfaces. |
| Inclined | Making an angle with another line or plane. |
| Inscribe | To draw a figure inside another figure. |
| Interference fit | Class of fit where interference is always maintained between mating parts. |
| Isometric drawing | Pictorial drawing showing three connected planes of an object represented in two dimensions. |
| Isosceles triangle | Triangle having two sides and two base angles equal. |
| Key | Small piece of metal fitting in both the shaft and hub to prevent circumfrential motion. |
| Keyway | Slot in a hub or portion surrounding a shaft to recieve a key. |
| Lathe | Machine used to shape material by rotation around a tool. |
| Leader | A line drawn from a note to the object where the note applies. |
| Level | Transparent layer where entities are generated and recorded on CAD drawings. |
| Limit dimensioning | Dimensioning system where class of fits are controlled by applying tolerances and allowances. |
| Mechanical drawing | The darfting of drawings dealing with primarily mechanical objects. |
| Micrometer | Instrument used to measure thickness (diameter) with precision. |
| Nominal size | The specified size of an object, which may not be its actual size. |
| Oblique angle | Angle that does not caontain 90 degrees. |
| Oblique drawing | A pictorial drawing showing one face parallel to the viewer. |
| Obtuse angle | Angle containing more than 90 degrees. |
| Octagon | An eight-sided geometric shape. |
| Orthographic projection | The method used to represent two- and three-dimensional objects using standard views. |
| Parallel | Two or more lines or planes that are always the same distance apart. |
| Parallelogram | A four-sided plane figure that has two pairs of parallel sides. |
| Pattern | Model used in forming a mold or a casting. |
| Pentagon | Five-sided geometric shape. |
| Perimeter | Distance around the outside of a geometric figure. |
| Perpendicular | A line or plane 90 degrees to another line or plane; at right angles. |
| Perspective drawing | Pictorial drawing that closely approximates the actual optical image of an object. |
| Pitch | The distance from one point on a screw thread to the same point on the next thread. |
| Plot plan | A map or drawing of an area that shows boundaries of lots and other parcels of property. |
| Polygon | Plane figure bounded by straight lines. |
| Protractor | A drawing device used to measure angles. |
| Radius | One half the diameter of a circle. |
| Ream | To enlarge a hole slightly to give it greater accuracy. |
| Rectangle | Geometric shape having four straight sides and four 90-degree angles. |
| Right angle | An angle containing 90 degrees and two perpendicular lines. |
| Rivet | Small fastener used to join objects together. |
| Round | The outside rounded corner on a casting. |
| Scale | A measuring device used to lay out or measure distances. |
| Scalene triangle | A triaangle having three unequal sides. |
| Schematic | A diagram usually containing electric or electronic circuitry and symbols. |
| Sectional view | A view of an object showing interior detail. |
| Shaft | A revolving bar, usually cylindrical, serving to transmit motion. |
| Shim | A thin piece of material used as a spacer in adjusting two parts. |
| Spotface | To produce a shallow circular bearing surface beneath the surface of a part. |
| Structural drafter | Person who prepares drawings dealing with the structural portions of buildings. |
| Surveyor | Person skilled in land measurement. |
| Symmetry | Correspondence of form and arrangement of parts on opposite sides of a boundary or axis. |
| Tangent | The point at which a straight line and curved lines meet. |
| Tap | The tool used to cut internal threads. |
| Tap drill | Drill used to make a hole for internal threads. |
| Template | Shape that is used as a pattern or guide. |
| Tolerance | Permissable variance in the size of a part. |
| Trapezoid | A plane figure havinng two parallel and two nonparallel side. |
| Tread | The step or horizontal member of a stair. |
| Triangle | A three-sided geometric figure. |
| Triangulation | A method of development using a system of imaginary triangles. |
| Truncate | To cut off a geometrical solid at an angle to its base. |
| Vellum | Semitranslucent drawing paper used to make whitepeints. |
| Vernier scale | Graduated scale used to obtain very precise measurements. |
| Volume | The amount of space occupied by an object measured in cubic units. |
| Weld | Uniting metal parts by pressure or fusion welding processes. |
| Whiteprint | A reproduction of a drawing having a light-colored background and bluish lines. |
| Working drawing | A drawing containing the necessary information that will allow someone to work directly from it. |
