Cutting tool geometries play important roles in tool performance, such as tool life, surface integrity, and cutting force. The most common commercial tools edge geometries are honed, chamfered and hone-chamfered. This study investigates new ways to develop tool geometry. An uncoated carbide tool is used in the orthogonal cutting of AISI 4140. By observing the tool geometry changes in the machining process with white light interferometry, a new tool wear geometry model has been proposed. A non-destructive tool wear measurement is discussed as well. In addition, this study presents the machining result comparison between the new and conventional geometries as well as the failure analysis from both experimental and FEA perspectives. / Thesis / Master of Applied Science (MASc)