ASME B46.1:1995 pdf free download – SURFACE TEXTURE (SURFACE ROUGHNESS, WAVINESS, AND LAY) SECTION 1 TERMS RELATED TO SURFACE TEXTURE
1.1.1 Scope. This Standard is concerned with the geometric irregularities of surfaces. It defines surface texture and its constituents: roughness, waviness, and lay. It also defines parameters for specifying surface texture. The terms and ratings in this Standard relate to surfaces produced by such means as abrading, cast- ing, coating, cutting, etching, plastic deformation, sintering, wear, erosion, etc.
1.1.2 Limitations. This Standard is not concerned with error of form and flaws, but discusses these two factors to distinguish them from surface texture. This Standard is not concerned with luster, ap- pearance, color, corrosion resistance, wear resis- tance, hardness, subsurface microstructure, surface integrity, and many other characteristics which may govern functional considerations in specific applica- tions.
This Section does not recommend specific surface roughness, waviness, or type of lay suitable for spe- cific purposes, nor does it specify the means by which these irregularities may be obtained or pro- duced. Criteria for selection of surface qualities and information on instrument techniques and methods of producing, controlling, and inspecting surfaces are included in the other sections and in the appendices.
The appendices shall not be considered a part of this Standard. They are included for clarification and in- formation purposes only. Surface texture designations as delineated in this Standard may not provide a sufficient set of indexes for describing performance. Other characteristics of engineering components such as dimensional and ge- ometrical characteristics, material, metallurgy, and stress must also be controlled.
1.2.2 Components of the Real Surface. The real surface differs from the nominal surface to the extent that it exhibits surface texture, flaws, and errors of form. It is considered as the linear superposition of roughness, waviness, and form with the addition of flaws. roughness – the finer irregularities of the surface texture that usually result from the inherent action of the production process or material condition. These might be characteristic marks left by the processes listed in Fig. B1 of Appendix B. waviness – the more widely spaced component of the surface texture. Waviness may be caused by such factors as machine or workpiece deflections, vibra- tion, and chatter. Roughness may be considered as superimposed on a wavy surface. lay – the predominant direction of the surface pat- tem, ordinarily determined by the production method used sugam texture – the composite of certain devia- tions that are typical of the real surface. It includes roughness and waviness. error of form – widely spaced deviations of the real surface from the nominal surface, which are not in- cluded in surface texture. The term is applied to de- viations caused by such factors as errors in machine tool ways, guides, or spindles, insecure clamping or incorrect alignment of the workpiece, or uneven wear. Out-of-flatness and out-of-roundness’ are typ- ical examples.
Jaws – unintentional, unexpected, and unwanted interruptions in the topography typical of a surface. Topography is defined in para. 1.5.1. However, these topographical interruptions are considered to be flaws only when agreed upon in advance by buyer and seller. If flaws are specified, the surface should be inspected by some mutually agreed upon method to determine whether flaws are present and are to be rejected or accepted prior to performing final surface roughness measurements. If specified flaws are not present, or if flaws are not specified, then interrup- tions in the surface topography of an engineering component may be included in roughness measure- ments.