The Relationship Between the Workpiece Extension Length/Diameter Ratio and Surface Roughness in Turning Applications

  • John Cooper (Southern Illinois University Carbondale)
  • Bruce DeRuntz (Southern Illinois University Carbondale)


The advancement of the lathe and subsequent modern technologies was made possible through research leading to the development of optimization tables that list specific feed rates, spindle speeds, and depths of cut for different materials. These tables are the standard used in industry as a source of reference, when making a change from one job to another where the machining parameters of each may be quite different. The time, material, and tooling costs associated with the experimental steps needed to find the appropriate machining parameters for each new job are eliminated, giving the company the advantage of a reduction in setup costs and improved product quality. While there are many machining optimization parameters that have been developed and put into tables, an area that has been overlooked is that of correlation between the unsupported workpiece extension length and the resultant surface roughness. The premise of this research is that the use of a tailstock in lathe work for workpiece support may sometimes be unnecessary. This idea is investigated to find out if there are instances where an unsupported workpiece can be machined with equivalent results to a supported workpiece in terms of surface roughness; so the time, labor, and materials used to center drill the workpiece and setup the tailstock are not used needlessly. Therefore, the focus of this study is to extend previously established research on effects of workpiece elastic deformations (Benardos, Mosialos and Vosniakos, 2006) and examine the relationship that exists between the length, at a specific diameter, and surface roughness of bar stock in both supported and unsupported turning operations in an attempt to reduce setup waste in turning operations.

Keywords: machine tools|manufacturing|materials and processes|metrology|quality control|research

How to Cite:

Cooper, J. & DeRuntz, B., (2007) “The Relationship Between the Workpiece Extension Length/Diameter Ratio and Surface Roughness in Turning Applications”, Journal of Industrial Technology 23(2).

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Published on
01 Apr 2007