Machinery's Handbook, 31st Edition
Surface Texture
809
Flaw
Lay
Waviness Spacing
Waviness Height
Valleys
Roughness Average — R a
Mean Line
Peaks
Roughness Spacing
Fig. 1. Pictorial Display of Surface Characteristics Surface, nominal is the intended surface contour (exclusive of any intended surface roughness), the shape and extent of which is usually shown and dimensioned on a drawing or descriptive specification. Surface, real is the actual boundary of the object. Manufacturing processes determine its deviation from the nominal surface. Surface texture is repetitive or random deviations from the real surface that forms the three-dimensional topography of the surface. Surface texture includes roughness, wavi ness, lay and flaws. Fig. 1 is an example of a unidirectional lay surface. Roughness and waviness parallel to the lay are not represented in the expanded views. Waviness is the more widely spaced component of surface texture. Unless otherwise noted, waviness includes all irregularities whose spacing is greater than the roughness sampling length and less than the waviness sampling length. Waviness may result from
Copyright 2020, Industrial Press, Inc.
ebooks.industrialpress.com
Made with FlippingBook - Share PDF online