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IED Unit 7
Term | Definition |
---|---|
1. 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 (for horizontal dimensions) and from the right side (for vertical dimensions). |
2. Allowance | The tightest possible fit between two mating parts |
7. Baseline Dimensioning | System of dimensioning in which all dimensions are placed from a datum and not from feature to feature. Also referred to as Datum Dimensioning. |
8. Balloon | A circle with a single number connected to an assembly component with a leader line to refer to parts. |
9. Bilateral Tolerance | A tolerance in which variation is permitted in both directions from the specified dimension. |
13. Clearance Fit | Limits the size of mating parts so that a clearance always results when mating parts are assembled. |
14. Counterbore | A cylindrical recess around a hole, usually to receive a bolt head or nut. |
15. Countersink | A conical-shaped recess around a hole, often used to receive a tapered screw. |
16. 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. |
17. Datum | A theoretically exact point, axis, or plane derived from the true geometric counterpart of a specific datum feature. The origin from which the location, or geometric characteristic of a part feature, is established. |
18. Datum Dimensioning | A dimensioning system where each dimension originates from a common surface, plane, or axis. Also known as baseline dimensioning. |
19. Decision Matrix | A tool used to compare design solutions against one another, using specific criteria. |
22. Dual Dimensions | Where alternate units are displayed within the same dimension. |
23. Fillet | An inside radius between two intersecting planes. |
28. Interference | The amount of overlap that one part has with another when assembled. |
32. Limit Dimensions | The largest and smallest possible boundaries to which a feature may be made as related to the tolerance of the dimension. |
34. Location Dimension | A location dimension that defines the relationship of features of an object. |
40. Pitch | A distance of uniform measure determined at a point on one unit to the same corresponding point on the next unit; used in threads, springs,and other machine parts. |
41. Reference Dimension | A dimension, usually without a tolerance, used for information purposes only. A reference is a repeat of a given dimension or established from other values shown on a drawing. Reference dimensions are enclosed in ( ) on the drawing. |
42. Round | An outside radius applied to corners. |
47. Spotface | A shallow recess like a counterbore, used to provide a good bearing surface for a fastener. |
50. Taper | Gradual diminution of width or thickness in an elongated object. |
52. Tolerance | The acceptable amount of dimensional variation that will still allow an object to function correctly.. |
53. Transition fit | Occurs when two mating parts can sometimes have a clearance fit and sometimes have an interference fit. |
54. Unidirectional Dimension | A dimensioning system which requires all numerals, figures, and notes to be lettered horizontally and to be read from the bottom of the drawing sheet. |
55. Unilateral Tolerance | A tolerance in which variation is permitted in only one direction from the specified dimension. |
56. Working Drawings | Drawings that convey all of the information needed to manufacture and assemble a design. |