Surface roughness model for worn inserts of face milling: Part I - Factorsthat affect arithmetic surface roughness

The roughness of face-milled surfaces changes with tool service time. A ser ies of tests was conducted to evaluate the trend in roughness change. As to ol service time increases the surface roughness decreases to a minimum, and then increases. A tool needs to be changed when surface roughness exceeds a design specification. In Part I, we discussed how the surface roughness i s affected by numerous factors, such as flank wear, crate wear, feed rate, speed, depth of cut, etc.. In Part II will recommend to least-square-fit th e roughness delta to a quadratic function of tool service time.