Sliding guideways are often used as the foundation of linear motion in computer numerical control (CNC) machine tools due to their high damping capabilities especially for heavy duty machining applications. However, the traditional manufacturing process with grinding is time consuming and the product’s sliding performance has not been optimized nor clearly understood. In order to increase productivity, a machining center based manufacturing method with CBN milling tools was introduced and tested by researchers. While greatly reducing manufacturing time and cost, a rougher milled surface, in comparison to traditional grinding, is a possible concern for the performance as well as the life of sliding guideways. In this study, a novel planar honing process was proposed as a post process of CBN milling to create a finish surface on hardened cast iron sliding guideways used for CNC machine tools. A design of experiment (DOE) was conducted to statistically understand significant factors in the machining process and their relationship with surface topography. Effective planar honing conditions were discovered and analyzed with 3D and 2D surface parameters.