Metalworking Is Literally a High-Pressure Business
You watch as a seasoned blacksmith takes a piece of red-hot iron with tongs out of the forge and lays it on his anvil. He picks up his heavy hammer and starts to beat the metal into a shape. You marvel at the skill of this craftsman in shaping the metal to his will, perhaps comparing him to a sculptor. While that is an apt analogy, what you are witnessing is also one of the most ancient examples of what is essentially a stamping press in action—heavy downward force applied to a malleable workpiece that is positioned on an immovable surface.
The use of pressure to deform metal is the most basic example of metal fabrication and has application in several machines found in the typical shop. Brakes, shears, punches, and other tools use the principle of pressing—often at high speeds—to do their work.
The traditional metalworking press—a machine that utilizes platens or tooling to flatten or shape metal workpieces under pressure—is a mainstay of metalworkers of every level, whether they just have a small shop press tucked in a corner for occasional projects or a massive hydraulically powered machine located front and center for everyday use.
A Brief History of Presses
One of the earliest tools known to humans is the press. The idea that pressure—applied either through human force or through gravity—combined with two hard surfaces could flatten, crush, or otherwise transform an object between those surfaces goes back to the first time a rock was used to crack open a nut against another rock. As woodworking, stone working and eventually metalworking advanced, the use of two flat plates that could press an object between them while mounted in some sort of mechanism has been a constant in production work the world over.
Power sources for presses over the millennia have taken a variety of forms, including:
The pinnacle of press power sources, hydraulic, offers the advantages of producing higher amounts of force, distributing that force uniformly across the platen, and allowing a slower ram speed during the actual forming than throughout the rest of the operation for better control and less chance of damage to the workpiece.
Along with just squeezing or flattening a workpiece, press developers over the centuries have introduced non-flat tooling into use with press mechanisms for such functions as printing paper, embossing different materials with a design, punching holes, or cold forging parts. The concept of the press brake is simply the application of a powered press combined with a metal-bending brake.
Types of Metalworking Presses
Presses can be classified in several ways, from function to power source to frame type. Here are some of the designations of presses that are used in metalworking:
Finding the Right Press for Your Application
Some questions to ask when shopping for a press include:
These simple questions can help determine whether you can get by with a manually operated press, need to purchase an air or electric press, or must acquire a hydraulic press for your operation.
Be sure to look at all options carefully and talk to qualified—and trusted—press distributors to get the best idea of what press you need for your shop or plant.