1. Lathe/Turning Machine
Lathe machines are used for shaping metal (or other materials) round by holding and rotating the workpiece while a carbide tool bit is advanced into the work causing a chip removing cutting action. Holding the part is normally done with a chuck that has jaws to grip the part at one end and a pointed center to support the center of the part at the other end. Lathes may also be able to produce screw threads, tapered work, drilled holes, knurled surfaces, and crankshafts depending which tooling is used and options are chosen. Slight differences in the various engine lathes make it possible to group them into four categories: lightweight bench type, precision tool room type, gap type and big bore. Precision tool room lathes are used for all operations, such as turning, boring, drilling, reaming, producing screw threads, taper turning, knurling, and radius forming.
2. Milling Machine
A milling machine is a machine tool used to machine solid materials. Milling machines are often classed in two basic forms, horizontal and vertical, which refers to the orientation of the main spindle. Both types range in size from small, bench-mounted devices to room-sized machines. Unlike a drill press, which holds the workpiece stationary as the drill moves axially to penetrate the material, milling machines also move the workpiece radially against the rotating milling cutter, which cuts on its sides as well as its tip. Workpiece and cutter movement are precisely controlled to less than 0.001 in (0.025 mm), usually by means of precision ground slides and leadscrews or analogous technology. Milling machines may be manually operated, mechanically automated, or digitally automated via computer numerical control (CNC).
3. Grinding Machine
A grinding machine, often shortened to grinder, is a machine tool used for grinding, which is a type of machining using an abrasive wheel as the cutting tool. Each grain of abrasive on the wheel's surface cuts a small chip from the workpiece via shear deformation. The grinding machine consists of a power driven grinding wheel spinning at the required speed (which is determined by the wheel’s diameter and manufacturer’s rating, usually by a formula) and a bed with a fixture to guide and hold the work-piece. The grinding head can be controlled to travel across a fixed work piece or the workpiece can be moved whilst the grind head stays in a fixed position. Very fine control of the grinding head or tables position is possible using a vernier calibrated hand wheel, or using the features of numerical controls.
