ASME Y14.36-2018 pdf – Surface Texture Symbols.
4.4.7 RadiaL. The lay is approximately radial relative to the surface to which the symbol is applied. See Figure 4-3, illustration (fJ.
4.4.8 ParticuLate. The lay is nondirectional or protuberant (cast surface). See Figure 4-3, illustration (g).
4.5 SymboL PLacement
The vertex of the symbol’s angled legs shall be placed
(a) on a line representing the surface
(b) on an extension line of the surface
(c) attached to the horizontal portion of a leader line directed to the surface, or
(d) attached to a feature control frame directed to the surface
The symbol may be specified with a diameter dimension. When the basic surface texture symbol is used, with or without MRR, NMR, or APA, it may be applied at any angle. When the expanded surface texture symbol is used, the parameter information shall be read from the bottom of the drawing graphic sheet (see Figure 4-4).
4.6 TextuaL Presentation of Surface Texture Requirements
When surface texture requirements are presented as a textual entry, the standard display method illustrated in Figure 4-5 shall be used. The letters relate to the surface texture parameters (see para. 4.5 and Figures 4-2 and 4-5). The lay symbol abbreviations used in the textual presentation are as shown in ASME Y14.38. Use “MULTD” for the multidirectional lay abbreviation.
4.6.1 Sequence Format. The text positions for data entry sequence shall be in the order shown in Figure 4-2. Two forward slashes are used to divide separate parameter sequences after item “d.”
5 APPLICATIONS AND ASSOCIATED VALUES
5.1 AppLicabiLity of ControLs
When a surface texture symbol is used, it relates to the entire surface or area to which it is applied. Surface texture requirements comprised of either symbols or the textual presentation method may be applied by the use of general notes, contained in a title block, or defined in other specifications. Surfaces that require different parameters than those stated in the title block or other specification shall be identified in the field of the drawing with their own surface texture symbols and requirements. Only those items or values necessary to specify and verify the required surface texture characteristics shall be included (see Figure 4-4). See ASME B46.1 for default values.
5.1.1 Areas of Transition. Features that blend or transition between surfaces, such as chamfers, fillets, and cutter ramps, shall conform to the roughest adjacent finished area unless otherwise specified.
5.1.2 PLated or Coated Surfaces. Drawings or specifications for plated or coated parts shall indicate whether the surface texture values apply before, after, or both (see Figure 5-1).
5.1.3 SingLe Surface ControL. Unless otherwise specified, the surface texture requirements apply only to the indicated surface.
5.1.4 MuLtipLe Surface ControL. A single surface texture control may be applied to multiple surfaces using multiple leaders as shown in Figure 4-4 or by using the all-around or all-over modifiers. The use of modifiers is limited to the graphic symbol oniy (see Figures 5-2 and 5-3).
5.1.4.1 AppLication of ALL-Around Modifier. When the same surface texture is required on all surfaces around a part outline, the surface texture symbol may be modified to apply all around. This is achieved by adding the all-around symbol to the intersection of the angled and horizontal leg of the surface texture symbol. In an orthographic view, the symbol is applied to an edge of a surface that represents a closed outline. See Figure 4-1, illustration (e) and Figure 5-2. Only eight surfaces shown on the 3D representation of the part are controlled by the all-around modifier applied in the orthographic view (the front and rear surfaces not included). Surfaces shall be indicated independently if any ambiguity arises from the all-around indication.