Search results
Results from the WOW.Com Content Network
Geometric dimensioning and tolerancing (GD&T) is a system for defining and communicating engineering tolerances via a symbolic language on engineering drawings and computer-generated 3D models that describes a physical object's nominal geometry and the permissible variation thereof. GD&T is used to define the nominal (theoretically perfect ...
ASME Y14.5 is a complete definition of geometric dimensioning and tolerancing. It contains 15 sections which cover symbols and datums as well as tolerances of form, orientation, position, profile and runout. [3] It is complemented by ASME Y14.5.1 - Mathematical Definition of Dimensioning and Tolerancing Principles.
Run-out or runout is an inaccuracy of rotating mechanical systems, specifically that the tool or shaft does not rotate exactly in line with the main axis. For example; when drilling , run-out will result in a larger hole than the drill's nominal diameter due to the drill being rotated eccentrically (off axis instead of in line).
A material condition in GD&T. Means that a feature of size is at the limit of its size tolerance in the direction that leaves the least material on the part. Thus an internal feature of size (e.g., a hole) at its biggest diameter, or an external feature of size (e.g., a flange) at its smallest thickness. The GD&T symbol for LMC is a circled L.
Tolerance analysis is the general term for activities related to the study of accumulated variation in mechanical parts and assemblies. Its methods may be used on other types of systems subject to accumulated variation, such as mechanical and electrical systems.
Model-based definition (MBD), sometimes called digital product definition (DPD), is the practice of using 3D models (such as solid models, 3D PMI and associated metadata) within 3D CAD software to define (provide specifications for) individual components and product assemblies.
Coordinate dimensioning was the sole best option until the post-World War II era saw the development of geometric dimensioning and tolerancing (GD&T), which departs from the limitations of coordinate dimensioning (e.g., rectangular-only tolerance zones, tolerance stacking) to allow the most logical tolerancing of both geometry and dimensions ...
Technical drawing with references and geometric specifications. A datum reference or just datum (plural: datums [Note 1]) is some geometrically important part of an object—such as a point, line, plane, hole, set of holes, or pair of surfaces—that serves as a reference in defining the geometry of the object and (often) in measuring aspects of the actual geometry to assess how closely they ...