Metal Fabrication Processes - What is CNC Punching?

Steel products are everywhere, from cars tojustifiable, buyers can turn to a process called CNC
computers to grills. The process of creating holes inPunching. Whereas Stamping is designed for high
steel to accommodate almost any metallic design canproduction runs of ten thousand parts or more, CNC
involve several entirely different methods:Punching is designed to optimize short run costs,
One method is called "milling," and in some casesinvolving part quantities of ten thousand pieces or
"machining," where holes are slowly ground into steelless. CNC Punching is by far the fastest way to put
by a powerful drilling machine not much different thanholes into steel without paying upfront for a punch
a hand drill-only on a much larger scale.and die stamping setup.
A much faster method for creating holes in steel isThe term "CNC" means "Computer Numerical
called "stamping," which involves a machine called aControl," which is a system of using computer
punch press. A punch press is able to quickly applytechnology to effectively manipulate machines in very
ten, twenty, fifty, or five hundred tons (or more) ofprecise ways. In the case of CNC Punching, a
pressure to a slab of steel. The press uses acomputer code is used to instruct a stamping
punch-and-die system, where the "punch" is amachine (similar to a punch press) to punch holes into
protruding element and the "die" is a flat surface withsteel. Whereas the stamping press can create a part
various recessed areas for the protruding element toin a single hit, the CNC punch press creates a part
stamp. The protruding element (usually on top)with multiple hits-very quickly. Usually a turret or
smashes into the steel (i.e. it "punches" or "stamps"tooling storage device feeds the correct punch and
the steel) with many tons of pressure, removing adie into the punching center of the machine. Then,
portion of the steel slap called a slug, which usuallythe machine receives precise commands from the
falls through the recession in the die. The wholecomputer in order to punch single holes in the
process can take less than a second and a completelocations specified by the computer program. Many
metal part is usually the result. This stamping processCNC punching machines can punch a hole in half a
is by far the fastest way to put holes into metalsecond or less. While the creation of the parts takes
products. Often, there is a very high cost forlonger, there is no need to wait for an expensive
creating a punch and die setup intended for a punchpunch and die system to be made.
press, although the rewards of such a system is thatMilling is used in cases where there are either only
the cost per piece is significantly less than any othertwenty parts or less (prototypes) or unusually thick
method after the setup has been created.or steel designs that are not appropriate for punching.
While a stamping operation is ideal for high productionStamping is used in cases where there are many
runs, sometimes million piece runs are not requiredparts to be made. CNC Punching is used to create an
and it is therefore not feasible or logical. Without highintermediate amount of parts. Which method you
production, it is usually difficult to justify the cost ofchoose will largely depend on how many parts you
a stamping setup.require.
When the cost of making a stamping operation is not