This chapter explores how to model customized internal threads and external threads. The Hole Wizard tool is preferred for creating standard internal threads, whereas Toolbox is preferred for creating standard external threads. However, when nonstandard threads are required, it is recommended to use the Hole Wizard tool for creating internal threads, whereas manual methods have to be used to create customized external threads. Editing Features or Modification of Part Model involves a proper understanding of the Feature Manager. The Unified Thread Standard (UTS) has the 60° profile as the International Organization for Standardization metric screw thread that is used in the rest of the world, but the characteristic dimensions of each UTS thread were chosen as an inch fraction rather than a round millimeter value. The UTS is currently controlled by the American Society of Mechanical Engineers/American National Standards Institute in the United States.