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ASME Y14.41-2003 pdf download

(4) Direct tolerancing methods, as defined in ASME Y14.5M, should only be used to define the size of a feature. Geometric tolerancing is the preferred method. (5) When query is required, a notation stating the requirement for query of the model or associated data shall be added to the drawing or in the general notes. (6) Rounding requirements for resolved dimen- sions shall comply with para. 7.1.1(c). (7) When tolerancing features, alignment of the annotation plane to the true profile is not required. (8) Values queried from the modelfor anyfeature(s) without any tolerance or datum target specifications assigned shall be reference dimensions. (9) Legibility requirements of ASME Y14.2M shall apply when the annotation is viewed perpendicular to the annotation plane. (10) Annotationinanygivenannotationplane shall not overlap other annotation in the same annotation plane when the model is viewed perpendicular to the annotation plane. (11) Annotation text within any given annotation plane shall not be placed over the design model when the model is viewed perpendicular to the annotation plane. (12) Visible gaps between extension (projection) lines and geometry, as defined in ASME Y14.5M, are not required on models. (b) Applicable to Models Only (1) All annotation shall be specified in one or more annotation planes. When a CAD software does not sup- port maintenance of annotation plane orientation rela- tive to the model, the model only method shall not be used. See para. 5.2.3. (2) The associated entities, annotation, and attri- butes shall be in agreement. See para. 5.2.1. (3) Resolved dimensions created from queried model values are considered the same as values specified in ASME Y14.5M as expressed dimensions. See Table 7-1. (4) The term TRUE, when used with a dimension, shall not be used on models. (5) Display of centerlines or center planes for fea- tures of size are optional. (6) To ensure the annotation is being interpreted as intended (for example the text could be upside down or backwards following rotation of the model) one of the following techniques shall be used: (a) Ensure the reading direction is updated after rotation of a model. (b) Include a means of determining the correct reading direction in each annotation plane applied to a model. (c) When using saved views, ensure the model is orientated in the intended view direction. For exam- ple, this may be accomplished by including a means of 5 determining the correct reading direction in the view. (7) Dimensions and tolerances may be shown to internal features without the use of a section. See Fig. 8-4(c). (c) Applicable to Drawings Only (1) Dimensions, tolerances, datum specifications, and notes may be shown in true profile views and refer to visible outlines, or appear in axonometric views. (2) Axonometric Views (a) The orientation ofthe annotation shall be par- allel to, normal to, or coincident with the surface to which it applies. (b) Annotation shall not overlap other anno- tation. (c) Annotation shall not overlap the part. 3.1.2 Design Model Requirement. A design model is required and shall be in accordance with para. 3.2 and Section 4. 3.2 General Model Requirements The following paragraphs describe general require- ments for a model. 3.2.1 Associativity. The ability to associate digital ele- ments shall be available and maintained. Associativity information shall be electronically accessible. 3.2.2 Model Coordinate Systems. A design model shall contain one or more model coordinate systems. A model coordinate system shall be depicted by three mutually perpendicular lines segments with its origin located at the intersection of the three axes. Each axis shall be labeled and the positive direction shown. Model coordinate systems shall be right-handed unless otherwise specified. See Fig. 3-1. 3.2.3 Applications of Supplemental Geometry. When supplemental geometry is used, there shall be a clear distinction between the supplemental geometry and the design model geometry. (a) Represented Line Element. The following geometric tolerances may use a represented line element to clarify the directionality of a two-dimensional tolerance zone of parallel lines. When a represented line element is used to indicate the direction of a geometric tolerance application, the leader from the feature control frame shall terminate on the represented line element in an arrowhead. See Fig. 10-4. (1) Straightness applied to the line elements of a planar surface. See Table 10-1 and Fig. 10-4. (2) Orientation tolerance applied on an Each Ele- ment basis. See para. 10.2.2(a) and Fig. 10-9. (3) Line profile. See para. 10.2.3(g) and Fig. 10-20. (b) Associativity. The represented line element, the fea- ture control frame, and the controlled feature should be organized as an associated group. See Figs. 10-4, 10-9, and 10-20.

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