 What are machine tools? A machine tool is a power-driven machine used for producing the components of required shape and size with desired accuracy and surface finish by removing material from the workpieces. Workpieces are normally classified according to criteria. First, according to the desired purpose as single-purpose, multi-purpose or special-purpose machine tool. Second, according to the size of chip removed as machine tools with small size chips like grinding machine, polishing machine or machine tools with larger size chips like lathe machine and drilling machine. When we speak about machine tools, one of the most important types of tools are, first, the lathe machine, a machine tool which holds the workpiece securely between tool rigid and strong supports while the workpiece revolves. The cutting tool is originally held and supported while being found against revolving workpiece. A lathe machine generally includes the following parts A, led, B, headstock, C, trailer, D, garage, E, feed mechanism and F, credit-cutting mechanism. It can perform a wide range of operations letting through straight turning, step turning, eccentric turning, taper turning, facing, drilling, dreaming, mooring, knurling and thread cutting. Second, the drilling machine embraces holes in the solid material using a drill fitted in a drill chunk. The rotating drill is made of harder material than that of the workpiece and it is fed using a hand or power feed. High amount of heat generated during the process makes use of coolant and acidity. The basic elements of a drilling machine constitute of A base, B column, C work table, D, drill head, E, spindle, drive. A typical drilling machine can perform a wide variety of operations that include drilling, dreaming, mooring, counter boring, counter sinking, spot fixing, tapping, etc. Third, milling machine. Milling is a process in which the material moving takes place due to cutting action of a revolving cutter. The machine tool on which the milling operation is performed is called as a milling machine. A milling machine contains the following elements A, base, B column, C, knee, T, table, E, saddle, F, over arm, and arbor. A milling machine can carry out a lot of operations including plane milling, angular milling, form milling, slot or groove milling, saw milling or slitting. And grinding is a process of removing the material by the abrasive action of a revolving wheel on the surface of workpiece. The removal takes place in the form of small clips. Generally, the grinding wheel is mounted on a spindle driven by an electric motor. Due to the small size of the chips, grinding is considered as a wedging operation. Grinding machines are normally classified into two types. First, rough or non-president grinders. Second, fine or prescient grinders. Fifth, broaching machines. Broaching is a machining operation in which a tool called as approach is used to make a small cut through the surface of the metal. The approach is either pushed or pulled with the help of a broaching machine. Approach is capable of removing material as deep as 6 mm in one stroke and is hence used to produce a variety of shapes. Broaching machines are classified on a myriad of categories like power employed, direction of movement of broach, cutting cycle, type of drive and a number of mill heads. Sixth, honing machines. Honing is an abrasive machining process that produces a precision surface on a metal workpiece by scrapping an abrasive stone against it along a controlled path. Seventh comes lapping machines. Lapping is also an operating process used for improving the surface, finished for reducing the roughness on the surface. A lapping machine normally consists of a seizurey upper blade and a rotary blade. The workpiece is loaded in a conditioning rings on the lower plate. Lapping is mainly used for smoothing engine walls, surface plates and crank shafts. No machine tools are complete without the use of gears. Gears are manufactured from both metals and non-metals, like gas iron, brass and aluminum. Generally, all gears are cut through gear generating process, which are first, gear shaper process. A pinion shaped cutter is used in the process, which carries the tooth profile to be cut. A gear blank is introduced by the help of sliding head and is cut using a tool and throw motion. It is suitable for medium and large size batches. Second comes hobbing process. The cutter used in this process is called hobber, which is a warm light structure that carries a profile parallel to its axis. The hob is rotated at a suitable speed and fed into the gear blank. Hence comes the end of the good revision of the machine tools. It's time for this episode's question. What are multi-tasking machines? It's time to answer our last episode's question. What is use of lubricants in forging? The lubricant is used as a thermal barrier to restricting transfer from the workpiece to the dime. It also acts as a parting compound to prevent the part from sticking to the workpiece. So like, subscribe and comment with your feedback to help us make better videos. And thanks for watching. In the next episode of Mechanical Engineering Insiders, find out what joining processes are.