ASME Y14.3:2003 pdf download

ASME Y14.3:2003 pdf download.MULTIVIEWAND SECTIONALVIEW DRAWINGS
1 GENERAL
1.1 Scope This Standard establishes the requirements for creat- ing orthographic views for item description. The topics covered include the multiview system ofdrawing, selec- tion, and arrangement of orthographic views, auxiliary views, sectional views, details, and conventional draw- ing practices. Space geometry and space analysis and applications are included in the appendices for informa- tional purposes. 1.2 References The following documents form a part of this Standard to the extentspecified herein. The latestissue shallapply. ASME Y14.1, Drawing Sheet Size and Format 1 ASME Y14.1M, Metric Drawing Sheet Size and Format 1 ASME Y14.2M, Line Conventions and Lettering 1 Publisher: The American Society of Mechanical Engi- neers (ASME International), Three Park Avenue, New York, NY 10016-5990; ASME Order Department: 22 Law Drive, Box 2300, Fairfield, NJ 07007-2300 ISO 128-30, Technical Drawings — General Principles of Presentation — Part 30: Basic Conventions for Views 1 Publisher: International Organization for Standardiza- tion (ISO), 1 rue de Varembe´, Case Postale 56, CH- 1211, Gene`ve 20, Switzerland/Suisse
1.3 Definitions adjacent views: two adjoining orthographic views aligned by projectors. related views: two views that are adjacent to the same intermediate view. true geometry views: views that show the actual shape description, and when it is a section view it shows the actual shape cut by the cutting plane.
1.4 Orthographic Projection Orthographic projection is a system of drawing com- posed of images of an object formed by projectors from the object perpendicular to desired planes of projection.1.5 Orthographic View An orthographic view is the figure outlined upon the projection plane by means of the system of orthographic projection. Such a view shows the true shape ofa surface parallel to the projection plane (area ABCD with hole in Fig. 1). When an area is not parallel to the plane, the view of the area will be foreshortened (area BCEF in Fig. 1).
1.6 Projection Systems The two internationally recognized systems of projec- tion are third angle projection and first angle projection. Unless otherwise stated, this Standard features third angle projection. 1.6.1 Third Angle Projection. Third angle projection is the formation of an image or view upon a plane of projection placed between the object and the observer. Third angle projection is the accepted method used in the United States. See Fig. 2. 1.6.2 First Angle Projection. First angle projection places the object between the observer and the plane of projection. This method of projection used in some countries is herein described, in consideration of the need to interchange engineering drawings in an interna- tional market. See Fig. 3. 1.6.3 View Relationships. Note that the orthographic views of the object have the same configuration in both the first and third angle projections, but the placement of the views with respect to one another is different. The visibility of lines is always taken from the observer’s point of view. See Figs. 4 and 5.
1.7.2 Removed Views. Under certain conditions it may be impracticable to place a view in its normal aligned position. In this instance, viewing indicators are used to indicate from where the view was taken, and the view is removed to another location on the field of the drawing. See Fig. 9. Removed views are preferably shown on the same sheet from which the view has been taken. The removed view is identified using the view letters. The removed view may be drawn at the same scale as the view from which it is taken, or it may be drawn at a noted scale. It is also permissible to use a combination of numbers and letters for removed view identification. 1.7.3 Identifying Removed Views. To relate the view- ing plane or cutting plane to its removed view, capital letters such as A, B, C, etc., are placed near each arrow- head. The corresponding removed views are identified as VIEW A-A, VIEW B-B, VIEW C-C, etc. View letters should be used in alphabetical order excluding I, O, Q, S, X, and Z. When the alphabet is exhausted, additional removed views shall be identified by double letters in alphabetical order, as in AA-AA, AB-AB, AC-AC, etc. 1.7.4 Removed Views Alternative Practice. When using the reference arrow method, a single reference arrow and view letter are used to identify removed views. See Fig. 10.