IntroductionAutoCAD is a commercial software application for 2D and 3D computer-aided design (CAD) and drafting available since 1982 as a desktop application and since 2010 as a mobile web- and cloud-based app marketed as AutoCAD 360.AutoCAD is developed and marketed by Autodesk, Inc.The native file format of AutoCAD is .dwg.Autodesk has developed a few vertical programs for discipline-specific enhancements. This includes AutoCAD Architecture, AutoCAD Civil 3D, AutoCAD Electrical, AutoCAD ecscad, AutoCAD Map 3D, AutoCAD Mechanical, AutoCAD MEP, AutoCAD Structural Detailing, AutoCAD Utility Design, AutoCAD P&ID and AutoCAD Plant 3D. For example, AutoCAD Architecture permits architectural designers to draw 3D objects, such as walls, doors and windows, with more intelligent data associated with them rather than simple objects, such as lines and circles. Here, we will be studying AutoCAD Mechanical.Other softwares in market for CAD include solidworks, CATIA, ANsys, NX, etc. Every software has its own advantages and disadvantages over other. Softwares like solidworks are tailor-made for 3D modelling and easy to learn and use by an amateur. On the other hand, softwares like CATIA allow us to do 3D modelling as well as analysis of the object constructed. Hence, CATIA is more preferred when one has to do analysis of the 3D object modelled. AutoCAD is the most basic of all designing softwares. Its 3D modelling is not as powerful as that of other softwares, but is excellent for 2D drawings. In AutoCAD, one should mainly concentrate on learning 2D drawing. And then the 2D drawing of an object can be extended to construct its 3D model. This is in constrast with other designing softwares, where we first draw a 3D model of an object and then look it upon a plane to know its 2D drawing. Hence, in AutoCAD, the first step is to master in the art of 2D drawing. The 3D model can then be constructed with some more number of simple commands.Here, we will be using AutoCAD 2014.