Author: Tronserve admin
Sunday 25th July 2021 11:07 PM
Why Is It Called A Press Brake?
Question: Why is a press brake called a press brake? Why not a sheet metal bender or a metal former? Does it have to do with the old flywheel on mechanical brakes? The flywheel had a brake, like that on a car, allowing me to stop the motion of the ram before the forming of the sheet or plate began, or to slow the ram’s speed during forming. A press brake amounted to a press with a brake on it. I’ve had the privilege of spending a few years with one, and for many years I thought that was why the machine’s name is what it is, but I’m not sure that’s correct. It certainly doesn’t sound right, considering the word “brake” has been used to describe sheet metal bending long before powered machines came along. And press break can’t be correct, because nothing is broken or shattered.
Answer: Having pondered the subject for many years myself, I decided to do some research. In doing so I have the answer and a bit of history to relay as well. Let’s begin with how sheet metal initially was shaped and the tools that were used to accomplish the task.
From T-stakes to Cornice Brakes
Before machines came along, if someone wanted to bend sheet metal they’d attach an appropriately sized piece of sheet metal to a mold or a 3D scale model of the desired sheet metal shape; anvil; dolly; or even a forming bag, which was filled with sand or lead shot.
Using a T-stake, ball peen hammer, a lead strap called a slapper, and tools called spoons, skilled tradespeople pounded the sheet metal into the desired shape, like into the shape of a breastplate for a suit of armor. It was a very manual operation, and it’s still performed today in many autobody repair and art fabrication shops.
The first “brake” as we know it was the cornice brake patented in 1882. It relied on a manually operated leaf that forced a clamped piece of sheet metal to be bent in a straight line. Over time these have evolved into the machines we know today as leaf brakes, box and pan brakes, and folding machines.
While these newer versions are fast, efficient, and beautiful in their own right, they don’t match the beauty of the original machine. Why do I say this? It is because modern machines are not produced using hand-worked cast-iron components attached to finely worked and finished pieces of oak.
The first powered press brakes appeared just about 100 years ago, in the early 1920s, with flywheel-driven machines. These were followed by various versions of hydromechanical and hydraulic press brakes in the 1970s and electric press brakes in the 2000s.
Still, whether it’s a mechanical press brake or a state-of-the-art electric brake, how did these machines come to be called a press brake? To answer that question, we’ll need to delve into some etymology.
Brake, Broke, Broken, Breaking
As verbs, broke, brake, broke, and breaking all come from archaic terms predating the year 900, and they all share the same origin or root. In Old English it was brecan; in Middle English it was breken; in Dutch it was broken; in German it was brechen; and in Gothic terms it was brikan. In French, brac or bras meant a lever, a handle, or arm, and this influenced how the term “brake” evolved into its current form.
The 15th century definition of brake was “an instrument for crushing or pounding.” Ultimately the term “brake” became synonymous with “machine,” derived over time from machines used to crush grain and plant fibers. So in its simplest form, a “pressing machine” and a “press brake” are one in the same.
A press brake doesn’t “step on the brakes” to bend, so why is it called a press brake? A brief history of a few words reveals the answer. Photo courtesy of Getty Images.
The Old English brecan evolved to become break, meaning to violently divide solid objects into parts or fragments, or to destroy. Moreover, several centuries ago the past participle of “brake” was “broken.” All this is to say that when you look at the etymology, “break” and “brake” are closely related.
The term “brake,” as used in modern sheet metal fabrication, comes from the Middle English verb breken, or break, which meant to bend, change direction, or deflect. You could also “break” when you drew back the string of a bow to shoot an arrow. You could even break a beam of light by deflecting it with a mirror.
Who Put the ‘Presse’ in Press Brake?
We now know where the term “brake” comes from, so what about the press? Of course, there are other definitions unrelated to our current topic, such as journalism or publishing. This aside, where does the word “press”—describing the machines we know today—come from?
Around 1300, “presse” was used as a noun that meant “to crush or to crowd.” By the late 14th century, “press” had become a device for pressing clothes or for squeezing juice from grapes and olives.
From this, “press” evolved to mean a machine or mechanism that applies force by squeezing. In a fabricator’s application, the punches and dies can be referred to as the “presses” that exert force on the sheet metal and cause it to bend.
To Bend, to Brake
So there it is. The verb “brake,” as used in sheet metal shops, comes from a Middle English verb that meant “to bend.” In modern use, a brake is a machine that bends. Marry that with a modifier that describes what actuates the machine, what tools are used to form the workpiece, or what types of bends the machine produces, and you get our modern names for a variety of sheet metal and plate bending machines.
A cornice brake (named for the cornices it can produce) and its modern leaf brake cousin use an upward-swinging leaf, or apron, to actuate the bend. A box and pan brake, also called a finger brake, performs the types of bends needed to form boxes and pans by forming sheet metal around segmented fingers attached to the upper jaw of the machine. And finally, in the press brake, the press (with its punches and dies) actuates the braking (bending).
As bending technology has progressed, we’ve added modifiers. We’ve gone from manual press brakes to mechanical press brakes, hydromechanical press brakes, hydraulic press brakes, and electric press brakes. Still, no matter what you call it, a press brake is merely a machine for crushing, squeezing, or—for our purposes—bending.