Arithmetic Surface Roughness of Turned Surface

Arithmetic Average Surface Roughness

Arithmetic average surface roughness is defined in Chapter 10. For n discrete measurements of surface distance from the reference height it is
AA = Ra = ( y1 + y2 + y3 ... + yn ) / n

Ra for Turned Surface Profiles

Figure 23-7 shows a lathe turned surface profile if cutting is only done by the tool nose.

When there is more relevant tool shape than just a circular section a more complicated surface profile results. For example, the exercise shows the general profile below.

© 2002 by Barney E. Klamecki all rights reserved.