The aim of this research is to study appropriate setting of parameters in the production process ofRod Push which affect quality characteristics such as diameter and surface roughness. Cycle time is alsoconsidered. The problem was done at a study plant and it was found that the actual process capability index(Cpk) of two quality characteristics was less than the manufacturer’s standard of 1.33. Central composite designwas used to examine Rod Push produced by CNC with 5 controllable process factors including three factorsfrom rough-cutting process (spindle speed, feed rate, and depth of cut) and two factors from finish-cuttingprocess (spindle speed and feed rate). The nuisance factor of CNC was cutting tool wear. After collectingall data, the appropriate setting was investigated. The new results indicated that the new condition yieldedthe better process performance index and shorter cycle time.