PLTW Engineering Unit 7 Key Terms PDF

C:\\Users\\lsmith\\Dropbox\\2014-15 Curriculum Release\\Templates\\Logos\\PLTW\_Engineering5.jpg **Unit 7 Key Terms** Key Term Definition ---------------------------------------------------------- -----------------------------------------------...

C:\\Users\\lsmith\\Dropbox\\2014-15 Curriculum Release\\Templates\\Logos\\PLTW\_Engineering5.jpg **Unit 7 Key Terms** Key Term Definition ---------------------------------------------------------- ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- **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 and from the right side. **Allowance** The tightest possible fit between two mating parts. 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. **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. Auxiliary View A view that is used to show features that are located on an inclined surface in true size and shape. **Balloon** A circle with a single number connected to an assembly component with a leader line to refer to parts. **Bilateral Tolerance** A tolerance in which variation is permitted in both directions from the specified dimension. Blind Hole A hole that does not go completely through the work piece. **Chain Dimensioning** Also known as point-to-point dimensioning where dimensions are established from one point to the next. **Clearance Fit** Limits the size of mating parts so that a clearance always results when mating parts are assembled. Counterbore A cylindrical recess around a hole, usually to receive a bolt head or nut. Countersink A conical-shaped recess around a hole, often used to receive a tapered screw. **Datum** The origin from which the location, or geometric characteristic of a part feature, is established. **Datum Dimensioning** A dimensioning system where each dimension originates from a common surface, plane, or axis. Also known as baseline dimensioning. **Detail View** A view that is used to show a magnified view of features that are too small to adequately specify in another view. **Dual Dimensions** Where alternate units are displayed within the same dimension. **Fillet** An inside radius between two intersecting planes. Full Section A sectional drawing based on a cutting plane line that extends completely through an object. **General Notes** Notes placed separate from the views; relate to the entire drawing. **Interference Fit** Limits the size of mating parts so that an interference always results when mating parts are assembled. **International Organization for Standardization (IOS)** This is a worldwide organization that creates engineering standards. **Least Material Condition (LMC)** The smallest size limit of an external feature and the largest size limit of an internal feature. **Local Notes** Connected to specific features on the views of the drawing. Also known as annotations. **Nominal Size** The designation of the size established for a commercial product. Parts List A list of materials or parts specified for a project. Also referred to as a bill of materials or BOM. **Reference Dimension** A dimension, usually without a tolerance, used for information purposes only and are enclosed in ( ) on the drawing. **Round** An outside radius applied to corners. **Section Lines** Thin lines used in a section view to indicate where the cutting plane line has cut through material. **Section View** A view that is used to show details not apparent on the exterior of the part. **Taper** Gradual diminution of width or thickness in an elongated object. **Tolerance** The acceptable amount of dimensional variation that will still allow an object to function correctly..