What is Metal Stamping:   
Metal stamping is the process in which small, simple or complex shapes are punched-out in a continuous sheet of metal (blank) by using instruments such as punches and dies. Complex shapes are generated by successively stamping the metal sheet with punches of different shapes, starting with a rough shape, to the final punch. Stamping is a high volume production method and machines called presses that can generate 100 or more strokes per minutes are used. By using metal stamping, pieces of metal can be made into a three-dimensional object from a flat piece of metal. The object will also be stronger than if it was machined by any other process. Metal stamping can also be used on a piece of metal to make a relief design.

The die is made of hardened casing or hardened steel, while the punch is made of carbide or hardened, precision, ground, tool steel. The stamping machine or press may be powered by hydraulics, pneumatics or electric.

There are various types of presses that are used in metal stamping. A forge press is used to turn the metal piece into a three dimensional object. A press brake is used to bend the metal to force it to change its shape. A punch press is used to punch holes into the metal sheet. A set of rollers may be employed to make the metal pieces either thinner or wider. This is done by feeding the metal through the set of rollers to flatten it out. A set of plates can be used to stamp various designs or reliefs into the metal pieces

Optimum clearance between the die and the punch is required for increased tool life. Proper layout of the blank, punch and die must be done to ensure the minimum waste of the blank material, with just the right amount of wall thickness between adjacent punched parts. In addition, edge beading and shoulder forming can also be done. Metals such as brass, aluminum, bronze, fiber, inconel and steel can be stamped. There is a maximum sheet thickness up to which the metal can be stamped.

The most common type of metal stamping is called progressive die stamping. In this method, the metal is fed through a number of different dies, or stamping stations, at the same time. This process enables the piece to receive an assortment of shapes or impressions at once. The advantage of this is that it speeds up the procedure as the metal sheet doesn't have to be taken out and reinserted to a new die station each time.
... What is CNC Machining:
... Computer numerical controlled (CNC) machine tools are the best tools to use for automated machining. The machines can be as simple as a drilling machine that drills a hole repeatedly or they can be huge complex devices that can machine large cylinder blocks in multiple designs.

CNC machines can be operated either unmanned or with a few operators manning a production cell of many machines. Once the program that is used to give the machining detail and the tools to be used, etc. is given, then the machinery can run by itself. They will change the tools in the ordered sequence; turn the component around so that a fresh face is exposed, and so on. Because these machines can run by themselves for hours at a time, they save you manpower. Usually roughing operations are done on other machines to save on productivity.

Because they are computer programmed, CNC machining is more accurate, consistent and precise than human operated machining as this system doesn’t require human adjustment for its settings. There are no errors in CNC machining as the machinery operates exactly as the computer programs it to. This enables complicated machining tasks to be performed repetitively and the finished product will be the same each time.

CNC machine operation is relatively easy to learn and to set up as you just have to enter the instructions into a computer program. You can also recall the machine’s previous settings instantly. This process allows you to save time as lengthy manual changeovers are not required.

CNC machines have two tables and an automatic pallet changer. This saves valuable time as it allows components to be machined on one table while a fresh component can be loaded on another. There are various types of CNC machines available such as: turning; drilling; grinding; and machining centers that perform milling, drilling, boring, tapping, and contour operations.
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... What is Welding:
... Welding is a metal joining process in which two pieces of metal, touching each other, are melted at the edges by a welding gun to fuse them together. When the metals cool down, a strong bond is created. Welding can be done by using either pressure or by using a filler material. The heat can be provided by an electric arc, a gas flame, laser, electron beam, ultrasound, the electrical resistance of the metals or through a chemical reaction. There are different types of welding processes such as spot welding, mig welding, tig welding, seam welding, projection welding, gas welding, resistance welding, induction welding, thermal welding, and forge welding, etc. Welding rods and electrodes are used in welding.
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